Ironically, it was nationality, not faith. In general religion doesn't play important role in former Yugoslavia. It's more of a new thing for nationalists, something that reaffirms their nationality, Serb/Orthodox, Croat/Catholic, Bosniak/Muslim. People in Serbia screaming in agony over Albanians destroying holy places in Kosovo didn't lift a finger to do something when those places were left to rot during communism.
the differecnes stretch far far far more than a mere language. and there are subtle differences especially in conversational forms of the languages.

and no it isnt right i think khomeini dying is a good thing as a religious leader, though as a man he left little to be desired (i dont like him in other words...... strongly)