Tag isn't very cool, but as long as I'm not debating for him, I'm fine.
The reason I listed Kid Vulcan is because of his limited exposure. I don't think there's enough information for my tastes. Man-Killer is also a bit stale. Feminazi stereotypes make me sad.

Also, Slipstream's power doesn't give him much offensive fighting tactics. Maybe teleporting his enemy high into the air and dropping them is a good tactic against, [insert random melee figher], but he'd be pounded in an instant by anyone else.
Black Goliath- Affirmative action has no place in the CoM.

Besides, how many size-shifters do we need?
Namor (Ultimate)- Is there really a difference between his normal counterpart and himself? If not, I say we choose one and stick with it.
Halloween Jack- What are we going to do with his absorption powers? Did we say it was okay for characters to use the knowledge of their previous fights, because his powers basically say that he can, and that might give him a huge edge over his enemies.