Not good for non-catholics, the urban working population, women, Jews ...
Yes, not very good at all. I was thinking that if Louis Napoleon does not stay with MacMahon he would return to Paris. This would have the advantage of avoiding the sudden collapse of the government structure and the siege of Paris. There would be some manifestations in Paris as there were IOTL, and they may become armed insurrections, but the lesser difficulties of the Parisian population and the presence of a tottering but still alive regime would avoid a full radicalization. The lower classes in Paris number more than 1 million (out of 2 million population) and there are some 100,000 political refugees from other European states almost unanimously republicans and leftists: in a Paris where the economy has almost stopped their lot will be a very hard one and it is most likely that with spring there will be another armed insurrection; still the government should be able to repress it and possibly without too much blood unless they panic, A lot depends on the health of Louis Napoleon (which is not good: his kidney stones are getting worse and worse), but it is quite likely that an armistice can be arranged by mid-September both on the northern front and at the siege of Metz and peace negotiations can start by the end of the month. Let's assume that they take place in Frankfurt, same as IOTL. The French delegation will be very different from the one that negotiated with Bismarck IOTL February 1871 although it is not guaranteed that it will be better: it will be heavily slanted toward the extreme right (the Mamelukes) and may include Count Palikao (if he is still prime minister - if the emperor decides to form a new government of Unite Nationale Ollivier may take his place) and the marquis de Gremont (or his replacement as Foreign Minister). Trochu should be the military advisor. If the government of UN is formed, both Thiers and Favre may be drafted for the negotiation (not a big advantage for France: IOTL Otto run rings around them both). In the meantime Pius IX decides to decamp to France when the last French troops are recalled home (but still leaves the commander of Papal troops with the order to oppose with force any Italian attempt to enter Rome: when Italian troops enter Latium on schedule the resistance is longer and bloodier and there is fighting in Rome too).
After a month of negotiation Bismarck grinds down the French resolve (the military situation is bad, Bazaine is still holed up in Metz and the imperial regime is weak) and gets the peace terms he wants: the fortifications of Metz, Strasbourg and Belfort will be demolished and France will not rebuild them in the future, Cochinchina and the protectorate over Cambodia are transferred to the NCG (= to Prussia) and reparation shall be paid by France (half the amount of IOTL since the war was shorter). Bismarck has not had the time to negotiate with the southern German states: no German empire proclaimed in 1871 ITTL; the liberal-nationals will be somehow unhappy but also that the issue of integrating the southern territories into the German Reich is deferred; Prussia will take the lead for the joint defense of the other members of the NCG and for the southern states too, and the "German Indochina" will be included in the Zollverein (Otto may be happy enough with the compromise, the conservatives too).
The peace treaty is signed in Frankfurt on 15 November and the siege of Metz is lifted. The Prussians occupy Strasbourg, Metz and Belfort pending the payment of the war indemnity. Bazaine rush to Paris in the attempt to capitalize on being at the head of the last undefeated French Corps (bullshit, but you know) but without success. The peace treaty is not well received by Parisian masses and there are continuous although sporadic outburst of violence. The government of National Unity does not survive and again count Palikao form a right wing government. The emperor is despondent and his health continues to deteriorate. On 31 December he abdicates in favor of his son, under a Regency Council, and goes into exile in England with the empress. New elections are called for mid April 1871 but will not be held: in March Paris erupts in a full insurrection. Napoleon IV, the Regency Council and the government flee to Fontainebleu. The insurrection is bloody but does not last: within two weeks the insurrection is repressed by loyalist troops under MacMahon (Bazaine is furious). The Prussian ambassador delivers a congratulatory message to the emperor in occasion of his return to Paris. The National Assembly is dissolved but no new elections are called: for the next two years the Regency Council will rule by decree in the name of the underage emperor. Nothing much happens for two years (the economy is in a slump, the Regency Council is divided with the Ultramontane faction pressing for help for the exiled pope, anti-foreigner riots are frequent in the major cities and antisemitism increases. The rural areas are calmer but tense: the young emperor is not popular and royalist sentiments start to emerge not just among peasants but also within the bourgeoisie and the administration. The only good news are the completion of the payment of war indemnities (1872: the Prussian occupiers evacuate the fortresses) and the marriage between the emperor and Gisela of Austria in June 1873. The end of the 2nd empire comes in March 1874: a strike in Lyons is broken by troops leaving a few dead on the ground. When the news reach Paris the capital erupts into insurrection. This time is much worse than in 1871: some of the regiments garrisoning Paris join the insurgency and the emperor and his young bride flee for Calais and thence a safe exile in England. It is the hour of Bazaine, who is now commanding the army camp at Chalons: he marches on Paris, where a Commune has been proclaimed, and after two weeks of bloody city fighting (the bloody days of May) the Commune is defeated. An obscure colonel, Georges Ernest Boulanger, distinguishes himself in the fight and is wounded in the attack of the Pantheon. Bazaine declares the dissolution of the empire, assumes ad interim dictatorial powers and calls a referendum for 1st September: a king of the House of Bourbon or a republic. The referendum returns a majority of almost 80% for the royalist option. Bazaine at the head of a delegation of notables goes to offer to Henri de Bourbon the crown of France.
I decided to draft this micro-TL just to put into perspective the political and economical situation of France and it is not written in stone.
Would this have tangible economic consequences? I admit I know only the most superficial stuff about French economics: All the money French banks invested in OTL Russia - where did it come from? Would less wealth be generated in this ATL France?
The regime that governs a country has obviously a strong influence on its economic outcome even if no country lives in isolation. However it's not so easy just to change a regime and see an immediate impact on the economic result. IOTL France economy went by cycles: over the period 1830-1860 economy rose pretty strongly and industrial production went with it (this happened under the Orleans and the first half of the Bonapartist regime); from 1860 to 1890 economy still rose, but very slowly and significantly below the inflation rate and industrial production did even worse, raising at a rate of 0.5% per year (second half of the Bonapartist regime and 3rd Republic. To get a more complete picture this factors in the liberalization of the law on public companies in 1867, the loss of the position of first financial center of Europe in favor of London, the agricultural crisis of the late 1870s-early 1880s when imports from the Americas started to undercut the agricultural sector in Europe and the big financial crash of 1882); after 1890 bot economy and industrial production rose, accelerating after 1905 and up to 1914. My point here is that the Orleans revolution in 1830 is not the only motor of the economic growth over the next 30 years, the revolution of 1848 did not influence too negatively the economic cycle but also that the first 10 years of Bonapartist regime most likely are at the root of the economic downturn of the next 20 years not forgetting the shock of the Franco-Prussian war (the economic reforms of the late 1860s did not kick in enough to start a new growth cycle); the reforms of the 3rd republic - even if partly vitiated by political instability - were successful and are probably at the root of the next economic cycle (I'd say that without the agricultural crisis the recovery might have started earlier, but the crash of 1882 is not serendipity: boom-and-bust cycles must always be assumed).
It is also necessary to consider the peculiarities of France: first of all the relatively low percentage of people living in large cities (30%) which compares with the 45% of British urbanites (and the 55% in the Low Countries) in the same period; second the very high percentage of workers in the agricultural sector (50% of able bodied workers which means 8.5 million people to which we must add women and children who are always a significant percentage of an agricultural workforce) compared with the percentage of able bodied workers in the industrial sector (25%); third the French predilection for smallish industries and artisans which resulted in a much larger fragmentation of industrial enterprises compared with UK, Belgium or Germany; fourth (and quite significant) the distaste (not to say virulent antagonism) with which both the extreme right and the extreme left regarded the nouveau riches, the entrepreneurs that where fast climbing the social hierarchies (and it is interesting that a lot of industrialists and entrepreneurs were not really proud f what they were doing even if money and success were abundant: there is the story of an industrialist from Normandy, a very successful one, who became minister during the 2nd empire. Not only he did neglect his factories but found better satisfaction in marrying his daughters in the peerage and gaining a title himself. While it was a common goal of many industrialists in Great Britain too to marry their offspring to a title, none of them would have been ashamed of his profession nor would he neglect his factories. The only parts of France where this way of thinking was not practiced were the Pays du Nord and Alsace-Lorraine).
Mind, I'm not an economist nor an economic historian. If you are interested in the economic history of France the must-read is "The French Economy in the XIX Century" by Maurice Levy-Leboyer. It's obviously a very dry book, but very well reserched and choke-full of figures.
The attraction of French banks for getting involved in foreign loans (often to the detriment of the national access to credit) was heavily criticized by contemporary economists too. However Levy-Leboyer demonstrates that the returns French banks were making on foreign loans were much higher than what they made out of domestic loans and that their business strategy was not absurd at all. The question then is why German companies in the 1870s financed their expansion by setting up bank facilities in countries where the banking system was more free and efficient than in Germany (mainly Switzerland and Belgium: Krupp financed the acquisition of very rich iron mines in northern Spain in this way, and the same did later Thyssen this time in France and Sweden) but the French industrialists were more reluctant to follow this path.
And not for the best of Spain. There might be some neo-feudalism with regional Carlist strongmen in the various parts of the kingdom, only nominally united by their loyalty to the king.
Not necessarily. While Carlism was big in promising to defend ancient authonomies I doubt it would have really approved any form of neo-feudalism. It looks more like a sponsor of the "one king, one religion, one country" motto.
General question: With a oppressive conservative king in madrid, what will happen in the colonies? I expect a German attempt to buy the Spanish East Indies, but what about Cuba and Puerto Rico? An earlier Spanish-American War in the late 1870s or early 1880s?
Philippines, Marianas, Guam: it would be quite possible that these dependencies might be ultimately sold either for cash or as a fee to pay in special circumstances (if it comes to a personal union between France and Spain for example). If Germany is already present in Indochina it might become a possible buyer (IIRC during the Spanish-American war the German Far East squadron was dispatched to Manila to create a fait accompli while Spain and Germany negotiated the sale. Dewey got there before of them and the defeat of the Spanish fleet killed for ever the opportunity).
Cuba and Puertorico are much thornier issues. From 1868 to 1878 Cuba was in revolt against Spain (the Little War): IOTL the 3rd Carlist war (1872-76) may have disrupted the Spanish forces on the island, but in the end the independentist movement was defeated. ITTL Carlos may have bigger fishes to fry, and not be interested enough or have spare troops and money to suppress the insurrection and Cuba might go on her own way (meaning as an informal protectorate of the USA who were the main investors on the island). The 1868 insurrection of Puertorico was immediately repressed by Spain but the autonomist party was quite active in the 1870s. If Spain let Cuba go, the same might happen for Puertorico too (other on his own or in some kind of federation with Cuba).
The alternative might be that Carlos keeps both islands (for the time being at least) and a solution is delayed by 10 or 20 years.