While I agree with you in that no one side is completely innocent, but I think you're making a mistake by lumping in the Serbs with bin Laden's Bosnian and KLA allies. The Serbs never threatened us; they were only fighting to hang on to what was theirs.
I have a hard time telling who the good guys were are this conflict sometimes as well. However I dont support taking sides in it either, especially when its obvious that the KLA has been involved in things contrary to US interests such as arms/drug trafficking and support for terrorism. In my view, It is against US interests and against the goals of the war on terror to even remotely support them in any way.
In the end further support for the KLA/UCK will only backfire. And much like what happened in Afghanistan, they may become foes further down the line.