Agree with you to a point about Croatia. Franjo Tuđman was cut from the same cloth as Milosovic, and both agreed to carve up Bosnia between them (you're certainly correct when you say that the Bosnians werejust stuck in the middle). I agree also that for the ordniary Serb the fear of the Croat Ustase was very real in their minds.
My point with relation to Ukraine though is that, like Milosovic and the Croat/Bosnian Serbs, Putin is playing on the historical fears of the Crimean Russians to further his own poltical agenda.
The fear is just that; fear, and there is no actual threat to the Russians in Ukraine from the Ukrainians (at least, there wasn't before all this kicked off).