Unless Kemen makes some serious strides in being evil I have a hard time seeing it. Right now he's mostly just a spoiled little brat who has daddy issues combined with a power trip. I don't see him rising to the level of the Witch King even with a ring as he is now.

As far as the balrog goes I have a hard time believing that the dwarves will be able to ignore that entirely for very long. It kind of seems like that is what the writers were setting up though which is silly.