Mixing different kinds of special weapons is a bad idea.
For example, having a missile launcher in a squad that wants to be moving closer to the enemy each turn is just a waste of a missile launcher.
I also think all of your aspiring champs should have bolt pistol + power fist. Plasma pistols are ok but not really worth the points investment imo.
Other than that it looks ok. I think it is lacking a bit in the AT department. Even if you have the combi-meltas, they aren't the best thing for relying on.