This was dealt with great detail over the years on this site. It started with Slovenia and Croatia. I really don't have time to give you much, so I will attempt to be concise and may miss some major points. So Here is the Gist.
When Croatia declared Independence, the first nation to recognize them as an independent nation was Germany. And since over 700,000 Serbs were slaughters in NAZI Croatian and Albanian death camps, they as you might image went ape over a 3rd German/Croatian alliance.
Now while the Croatians and Serbs are ethnically identical (same language, different alphabet), the Croatians are not multi-culturally tolerant. So the drove the Serbs out of the Krajina which resulted in 300,000 Serbs absorbed into Serbian refugee camps...
Anyway the Serbs are the only ones that have any multicultural tolerance because of historical and geographical reasons. Even today Serbia is only around 65% Serbian, as was Kososvo, ( the historical Serbian Heartland,) before the WWII death camps. Check that percentage against their neighbors. Serbian Multiculturalism is strangely a cultural imperative for them, which Field marshal Tito used effectively to screw the Serbs and consolidate Yugoslavia after WWII.
Look, I really don't have time for this, it is over 1000 years of history to understand what happened in the early 20th century alone. Which is necessary to even have a clue about the Yugoslav wars. Either do your own history research or just take my word for it, the Serbs are the Good Guys, the Croats are ok, (but can be a pain with NAZI tendencies,) and The Albanians are pure evil. As you said,"You're absolutely right about the "recent history" in the region - as soon as the Bosnian and Albanian Kosovars get some breathing room, they turned around on the Serbs in vicious acts of terrorism and brutality. We've been seeing that for years." That should read centuries, not years.
Your knowledge of Balkan history leaves a lot to be desired.