I know you can't assign a character that can use PC an action token to use a theme team. However, this puzzled me a bit.

THE ESSENCE OF ANARKY IS SURPRISE: Anarky can use Outwit. Anarky can use Probability Control if before using the power you remove an action token from an opposing character not currently taking an action.

If there aren't any opposing characters with an action token on them can I then assign Anarky a theme team PC since he doesn't meet the requirements to use PC on his own? the word "if" is what's throwing me off. if it said something like Anarky can use PC, when he does remove an action token... I could see it differently.

Must not be able to use Probability Control through another game effect

Even though it is conditional with the "if", Anarky can use Probability Control. While he can use PC, he cannot be given a Themed Team use of Probability Control.

On page 21 of the 2011 Rulebook regarding using Themed Team PC, the figure:
As far as I know any reference to being able to use refers to whether the powers is currently available for use. With that, the question is can Anarky currently use PC? No, therefore Anarky can be given a token.

Same thing with SM Brainiac 5:
if it is the opponent's turn, Brainiac 5 cannot currently use PC, therefore he can be given a token.

And again same thing with Nico Minoru. If she chose a power other than PC for Staff of One, she cannot currently use PC, therefore she can be given a token.

Which I believe leads to the tortured situation of using Outwit to counter PC on a character which then allows said character to be assigned an action token to use PC.

I agree with Brainiac being able to use TTPC on your opponents turn and not on his turn .
I agree with Nico Minoru as well, as you explained it.
I don't agree with Anarky because his PC is currently available to use,just because he does not meet the condition to use it at the moment does not negate that he can't use PC.