I think you guys a call awfully pessimist regarding the integration of Ireland. It had a a real shot of being successfully part of the UK right up until the Great War broke out.
So Morocco is to Spain as Brazil is to Portugal? That is pretty logical, at least moreso than moving to Mexico or something. What goes in the colonies is gonna be interesting in that case.
Even if Ireland was Protestant (a real possibility), I somehow doubt it would be the "acceptable" type of Protestant, i.e., a group clearly outside the Church of England and thus worthy of persecution. England and Ireland sharing the same faith seems very odd and rather unlikely.
Spain has plenty of people to make both their Latin American settler colonies and Morocco. Maybe less people in tropical hellholes that kill Europeans by the truckload and more to Morocco, as well as less restrictions on who in the Spanish Empire can migrate. I've found Spanish America to be very interesting how they incorporated indigenous peoples compared to the United States/Canada--it was accompanied with massive bloodshed, but they still incorporated the natives far more than the US or Canada have, for better or worse. Spain incidentally didn't care who migrated within their New World colonies, hence you could be obviously African or Native American and be considered "white" in New Spain--you'd need something like that in Morocco (plus maybe even allowing those sorts of people from New Spain to emigrate to Morocco). Could they do the same with Morocco? Maybe. But the Berbers could well end up like the American Indians who never got integrated, like those in the Mexican North, the Mapuche, etc. And I don't see Arab culture really ever going away, but maybe a plurinational society like Bolivia with Spaniards, Arabs, and Berbers in place of Bolivia's ethnic mix. They key that prevents Morocco from seceeding is the fact it is so close to Spain and would no doubt be very economically tied to Spain. But if Spain does as mediocre as OTL, it'll probably have a Catalonia-like secessionist movement anyway.
Sorry if I'm misunderstanding you. But the concept of "Limpieza de sangre" was one of the several ideological tools used by the Catholic Monarchy to assure that the spanish identity was based in common religion and common crown, since as you say there is no way to base it in common language etc, and we are talking also about a time before nationalism was a thing. The Limpieza de Sangre particulary was a way to strangle any possibility of disidence while having an internal "other" to be united against. The Inquisition was in a way a proto ideological police, a product of the Modern State. It was created by the crown after all. Even in 1812 the liberal Constitution of Cádiz had catholicism as official and only religion, because it would be hard to find any other common trait amongst "the spaniards from both hemispheres".
However the 1812 constitution could have been a first step, had the historical circumstances and timing been notably different. Regarding citizenship, it considered that "The spanish nation is the reunion of all spaniards from both hemispheres" and defined spaniard as "All the free men born and living in the domains of the Spains, as well as their sons".
So Morocco is to Spain as Brazil is to Portugal? That is pretty logical, at least moreso than moving to Mexico or something. What goes in the colonies is gonna be interesting in that case.
What would Spain be giving up in Latin America? Yes, the Spanish Empire was overextended, but you could consolidate Latin America and North Africa at the very least, and probably more. The problem areas of Latin America are the periphery--the Chaco region, Patagonia/Pampas, and the North of Mexico. But in theory, Spain has justification to hold that area down--it keeps the place functioning, and for the North of Mexico, the mines of Zacatecas and such are safe from random raids (unless Spain/Mexico messes up to get the Comanche raiding the place as they did in the 1830s/40s--preventable). I realise that Spaniards of importance considered Latin America overextended and proposed to "fix" that by effectively abandoning the place, but I'm not sure if it's exactly ideal. The ideal is Latin America's transition to a Canada sort of relation with Spain, if not tighter (which in theory, couldn't Canada have had that potential?).
But Spain could move people around the way they did in the American colonies. The last Spanish governor of California, Pio Pico, is often cited as an example of social mobility--if you could bribe (or otherwise convince somehow) the right people you were Spanish and at the highest racial categories, you could get somewhere. Pio Pico had known African and Native American ancestry, and it didn't matter. That's the sort of people Spain could in theory send to Morocco. That's the sort of model they could apply there--if a Pio Pico-type goes to Morocco, his Berber/Arab equivalent goes to Mexico or Peru or wherever.
No, Spain wouldn't give up Latin America, rather, in the possible POD I suggested, they would never get some parts of it in the first place. I think not getting Rio de la Plata could be bennefitial when it comes to consolidate the Spanish Empire in the rest of Latin America and North Africa. Frees a lot of settlers to go elsewhere (preferably North Africa), makes the Empire easier to defend (The UK attacked Argentina numerous times, and Spain failed to protect them in most of those occassions. This was one of the causes of the Independence, as it made Spain look bad in the eyes of the people in the colonies. The one time the UK attacked other Viceroyalty, New Granada, Spain was able to counterattack and give the UK one of its worst defeats) and also means that they won't have to deal with British, Portuguese or Native attacks. I also think that, if they put some effort into it, Spain could do a better job at assimilating the natives in the north of Mexico (after all, they managed to assimilate the ones in South America) and thus use them to protect and secure the northern territories. I think that the US or any other power would think twice before declaring a war on a powerful and united Spanish Empire, so we may see a smaller and weaker USA and more powerful New Spain.
Are we talking about the north of modern Mexico, or the (far) north of Mexico lost to the US in 1848? Because Spain did utterly horrible there, and Mexico somehow did even worse, though I suppose with Mexico's other issues, the far north was the least of their worry.
But Argentina seems a bit too much to just abandon. Who'd take it then? Brazil/Portugal? Bringing back Mexico again, if you wanted to trim fat off the Spanish Empire in the New World, I'd put New Mexico and Texas as the very first. I guess La Plata might as well come third, though--give it to Portugal or something, it isn't like Spain ever cared much in the 18th century about the place.
The North the USA stol... obtained in 1848. I know Spain was horrible when it came to administring that land, but Mexico did even worse. If Spain keeps Mexico, it should be at least better than OTL because instead of a succession of incompetent and terrible dictators and juntas we would have a stable regime which could take care and settle those territories.
We could have the Portuguese taking Argentina. We only need the Pope to move the line he used in the Treaty of Tordesillas a little to the left, and the coast, and by extension the interior of Argentina would be Portuguese. That would save a lot of problems for Spain, as the Portuguese attacked them several times for the area and the Spanish response was always ineffectual, which in turn angered the people in the colonies and would eventually be one of the causes of the Independence. I think that perhaps Texas is not that important, and the Spanish wouldn't probably be able to develop it anyway, but conserving Califormia and some other territories could be useful.
The North the USA stol... obtained in 1848. I know Spain was horrible when it came to administring that land, but Mexico did even worse. If Spain keeps Mexico, it should be at least better than OTL because instead of a succession of incompetent and terrible dictators and juntas we would have a stable regime which could take care and settle those territories.
We could have the Portuguese taking Argentina. We only need the Pope to move the line he used in the Treaty of Tordesillas a little to the left, and the coast, and by extension the interior of Argentina would be Portuguese. That would save a lot of problems for Spain, as the Portuguese attacked them several times for the area and the Spanish response was always ineffectual, which in turn angered the people in the colonies and would eventually be one of the causes of the Independence. I think that perhaps Texas is not that important, and the Spanish wouldn't probably be able to develop it anyway, but conserving Califormia and some other territories could be useful.
Spain grabbed New Mexico and Texas as protection for the silver-producing parts of northern Mexico. It turned out to be far more trouble than it was worth, since they had a whole new set of American Indians to deal with. Spain had a very poor showing OTL with the Comanche and Navajo (Mexico did even worse). The best solution is to split New Mexico from New Spain proper. New Mexicans didn't think much of the people in Mexico City (like lynching the governor they sent after he messed up in some battle against the Indians). Nuevo Mexico might as well be the whole of North America north of the Rio Grande, which to get back on topic, Spain could "absorb" like Britain did to Canada.
What do you mean for interior Argentina? The Cuyo region was pretty incorporated with Chile, moreso than what became Buenos Aires until the late 18th century or so. No need to give that place away, Spain was strong there.
Mendo de la Cueva y Benavídez was the governor of Buenos Aires until 1640, he was the cousin of Salvador Correia de Sá e Benevides, governor of Rio de Janeiro. After the Iberian Union was ended Salvador sent a letter to his cousins in Buenos Aires asking them to swear fealty to John IV of Portugal, not only because of their personal relations but because Buenos Aires had a good commercial relationship whith Rio de Janeiro. What if Mendo stay in power a little more and succesfully makes Buenos Aires slip away from Spain in 1640?
Interesting. Spain would be outraged, but I doubt they would take any action, really.
The question would be, do the people of Rio de la Plata accept it? Do you think they would?