Yeah I think it's just a matter of showcasing such intelligent with little drops and with taste, not make gaudy statements.
Pretty much, yeah. Comic Book writers aren't trained professionals in the sciences, so they tend to go overboard sometimes. Moon Girl is the "best" example about this. Personally I prefer feats being added over time.
Yeah Luthor having a freak accident to gain powers pretty much goes against the character.
True, but I wasn't talking about that. Kinda. I had this "idea" that you have Lex start off like any other super-genius, but slowly his hate for Kal takes him over, and he starts experimenting with Kryptonite, making his whole body toxic against Superman. This causes him to go from a ginger to a bald guy, and also boosts his intelligence to that OTT level.