...do a lot of the early episodes of the Original Series for Star Trek remind anyone of Suvians?

The first episode's about a creature that can assume the form of anyone else (and throws them out of character). The second is about a human teenager with mind powers and not enough emotional maturity to handle them wisely (thus forcing everyone on the Enterprise to cater to his whims for a bit). The third is also about a man who develops god-like powers (which also forces everyone on the Enterprise to deal with him, although they seem to have learnt from Charlie and don't readily play along). The fourth is about a virus that makes everyone OOC (or removes their inhibitions to the point where they seem OOC). The fifth is about the "impostor", or the evil!Character Replacement-like doppelgänger. The sixth features three women who use something akin to Aura of Smooth.

I mean, with all of that canonical experience with Sue-like powers, I find it unsurprising that the Lieutenant Mary Sue/Ensign Sue originated in that fandom. I bet it'd make for a really entertaining TOS-verse Sue parody (and if you've read one, could you send it my way? Thanks).