If I mind control Earth 2 superman can I use his white power free attack. It says beginning of your turn, but does that apply to you or the mind controlled character who would be making his first action? I guess by the saem account can you mind control a character and use their poison?
My guess would be no but....

The second part would be then does the rest of my force get the modifier to attack on the character superman damaged after he returns to his owners force? This is obviously moot if you can't use the power in the first place.

Well, to get technical, the action that Supes takes would actually still be part of your first action (the MC) not a second action. But your answer is still correct.

The only way to make this happen right now, is to use Possession.