I wonder why the hell it's not playing nice with me. I wouldn't think an addon could screw with that, in fact I'm pretty sure it's impossible. Come to think of it I'm not sure how the interface operates without...
Screw it. I think it's time I strip down the addons and reinstall 8.2. Maybe it'll fix this and a few other oddities.
Yeah, I have no idea what the hell was happening, and it doesn't make any sense.
I could use Esc to bring it up (which means that GameMenuFrame = table) but trying to access it (e.g., GameMenuFrame:SetScale(1.1) ) would fail, and print(GameMenuFrame) gave a nil. I tried to do a var=nil (one of the other frame names, can't recall which) and it still gave a table reference instead of nil. Copy/paste so no typographical errors.
Removed & reinstalled _retail_ and the code errors went away and it's all working normally now so that's awesome, but it's still I'm gonna to take some aspirin and alcohol, I think.