Kosov is a prospect worth following because of his superb size and grittiness combined with his skating, skills, and hockey sense. He's obviously not ever going to be one of the most skilled players on the ice, but he's very projectable and you can definitely see his chances for the NHL are very good(should he come over, which I think he will or else we likely wouldn't have drafted him). He protects and handles the puck much better than your typical 4th liner, and could possibly complement a couple of skill players very well.
Rocco irks people because of his evangelism, not his religion. It's the preaching mentality as someone else said. I'm probably one of the few in the middle, I don't really care, I only care if it becomes a distraction in the Panthers' locker room. But as someone else said, I think as he gets older and more exposed to the world, he'll mellow out a little. Not that I think it's a bad thing to be an extremely devout Christian, so am I but it's the way you express your beliefs outwardly and interact with others.