So Thanos’ ability to FREE make an attack, can you have him equipped with proxima midnites spear and use that ability for the free attack? Or exospex and pick Pen/Psy and use that in the free attack?

Thanos get to make an attack, close or range. He can only use powers that would trigger off that (like blades, claws, fangs).

Proxima's Spear requires a RANGE action, Thanos can't activate that, just a plain old ranged or close attack.

As for Exospex, any power that requires a RANGE, CLOSE, or POWER action also wouldn't work with a free attack. With that, you should be able to figure out any interactions on the PAC.

No.

Proxima requires a RANGE to activate. A FREE won't do it.

Psy-Blast also requires a RANGE to activate so it won't work either.

BCF does not trigger from an attack, it triggers when a character is given a CLOSE.

So you can't Mind Control someone to use BCF.

Nevermind, I misunderstood your statement.

D'oh! Thanks

You can use Exospec to give him Precision Strike, Steal Energy, Force Blast, Super Strength (but he won't be able to attack using Object since the requires CLOSE or RANGE).
You can also give him Sidestep, which he can use after being carried.

Not normally, but there are times it will work. Like with Penance, who can do BCF on a close attack.

and even then only Shriek could MC Penance as Penance has Battle Fury. Unless you outwit it of course.

Good point. Battle Fury has got to be the power I forget about most often. I always feel terrible when I realize late in a game that I carried somebody with battle fury, or I feel annoyed that I let shape change prevent a battle fury character from attacking, etc. One of these days I will remember battle fury. Maybe.