My apologies for the continuing absence, life is busy right now. The only hobby writing I find time for is
www.culina-vetus.de, in case you incline historiculinarily. So let me try this:
Not sure it has been elaborated on much, but what trajectory did Serbia take from 1908 onward? I remember they were, at least initially, intended to be subject to the overwhelming brunt of Austro-Hungarian diplomatic fury, and that they didn't make out with anything in the Balkan War analogue which led to the significant expansion of Bulgaria and the formation of a relatively large Albanian state (the latter apparently including Kosovo, with detrimental consequences to the Serbs living there). Were they able to do anything during the Augsleich Crisis or the Second Russo-German War, or have they been basically stuck in place since the first? And regardless of that, have they managed to build their state upward in the succeeding decades?
Imagine a country with all the rage and disappointment of post-WWI Germany, but none of its military and industrial potential. A place condemned to be laughed at or despised, but never taken seriously by the powers surrounding it. That is midcentury Serbia. A history of occupation, limitations regimes, reparations, especially the Bosnian Volunteer Militia that did policing for the Austro-Hungarians during the war, the way Vienna sat on every ambition and the international press (unfairly, but truthfully) reported Serbian irregulars' atrocities in the Balkan conflict all created massive resentment. The country received lots of refugees from the Kosovo and Bosnia-Herzegovina which didn't help matters at all. Its politics is a contest over who hates the outside world more and who is more truly Serbian, more orthodox, more true-blooded while its government (and the increasingly resented king) is forced to bow to every demand from Vienna.
A key moment in history comes when Serbia decides to not get involved in the second Russo-German war. Street protests and revolts rock the country, but the government that is ultimately toppled over it turns out vindicated. Russia's defeat takes some of the pressure out of the system, and in the end, ultranationalism loses steam because it cannot achieve anything. Modernising parties eventually get into government and the country links into the economic growth that happens in Austrian Illyria. Many Serbs move to Austria as guest workers. The place still sucks, but not as badly. In the end, it's just another East European backwater with the usual nationalist rhetoric and venal government, living on extractive industries and remittances. Belgrade actually turns into a pretty nice, culturally active city. Many tourists go there because it's picturesque and alcohol is cheap, but there is also a real art scene and a lot of innovation happening.
What is the aristocracy or upper class of the baden baden countries like? If they have aristocracy what is there relationship like with the nation and its people?
Depends - it's different in various countries. Generally, though, they have an aristocracy both of blood and of service, and the two are more closely intertwined than in Germany.
Some places, especially where the upper class is traditionally ethnically different from the peasantry, see considerable tension. Finland resolves it by basically pointedly inviting its Swedish-speaking minority to use Finnish in public. That works surprisingly well. In Poland, similarly, Polish is the language of the upper class and everyone learns it. The presence of large and cohesive German and Yiddish speaking communities makes a unity like Finland's impossible, though. In the Baltics, things get ugly in a low-key, simmering resentment way. The German-speaking upper class are protected by Berlin and they use it to the hilt, making no friends with their arrogant ways.
Generally, things go best where the ruling class integrate newcomers (say, decorated veterans and successful businesspeople) and adopt the national language in public. Where they stay clannish and use their own language.
Second aren't the upper class/ aristocracy pro-russian? Are they not all the pro russian elite prior to the baden Baden nations independence, who ruled the land with russian support?. How come they were allowed to stay?
It depends. Germany is a very traditional country when it comes to government, and has great confidence in its ability to co-opt local leaders. Any aristocratic family that wants to be part of the new order is welcome. At an individual level, there were issues (we talked about that with regard to Russian officers), but there is no blanket ban on Russian collaborators. These are different times.
Any aristocrats (or commoners) that retain Russian as their language, obviously, are not welcome. Ethnic identity is pretty fluid, though. If, say, the Rennenkampf family decided to be part of the new state of Livland and serve in its institutions, they would be welcome as Baltic Germans, but if they decided to move to Pskov and take the Czar's commission, they would be Russians. Plenty of German noble families have ancestry who fought under Danish, Polish, French or Austrian banners. They understand that kind of thing.
Of course a generation down, things are different. The old aristocracy needs to open its ranks to people who came up in the military (a lot of the leaders of the nationalist forces are commoners or lesser gentry, but they get the plum jobs in this new world), and one way of retaining their position is to become more Catholic than the pope on national matters. Many of the most vocal defenders of Finnishness were once proud graduates of Russian cadet schools.