If I were to mind control a fantastic four member who was on their last click, attack and roll snake eyes, would I be able to heal any 3 wildcards or FF members on my team when he died?

At the time of KO, the FF member was friendly to your figures, and so your figures would be the ones who could heal. Keep in mind, you must follow all normal rules for wildcard timing and restrictions---any FF members you have will get their clicks, but your wildcards only if you declared them, were not wildcarding another TA, etc.

Thanks for responding so quick - its such a rare situation that I doubt it will ever come up, but I now know that if I ever see anyone in that situation to declare the wildcards and position the probability control to try and use my habit of rolling 2's to my advantage.