This has always bothered me, What would of happened if the Kosovo uprising occurred during the the 1992-95 Bosnia war?
Also say After 1985 Hungary got really angry at Romania and decided that it was time to invade, Who would win for starters? and would any other country intervine in that conflict?
Kosovo... Well the Serbs would send their army in and battle rebels and crush protests. they wouldn't actively begin slaughtering "Shqiptars" en-masse, they would leave that to paramilitaries that they would arm as they pulled troops out to fight the Croats and Bosniaks. It might push the Americans to bomb Belgrade a few years early. That being said, if the Kosovars manage to throw the Serbs out, a lot of monasteries are being burned, likely with Serbs in them.
As for Hungary and Romania... countries don't get "mad" at each other. I'm unaware of any incident that occurred during the Balkan Wars between those two countries, so unless there is one and it somehow turns hot, nothing will happen. Hypothetically, I'm guessing Romania, they have their own oil reserves and I believe a stronger manufacturing base for a long war. Romania also has a significantly bigger population and military (more than 5 times bigger if you count reserves). They'll roll over Hungary unless Hungary gets foreign aid, which is unlikely.