So STOP is now defined in the PAC as " When this click is revealed due to damage taken from an opponent's attack, stop turning the dial. When this character would be healed by regeneration or support, it's healed one less click. Protected: outwit, post wave."

So does that mean stop clicks can't be outfitted at all? Or just the STOP ability? Like can you outwit toughness on a STOP click?

Any power that is part of a special power which includes STOP is protected for Outwit and Pulse Wave.
That has been the case since STOP had been introduced and it hasn't changed with rules update.