So for my WR pb on Treetop Temple I used Simple Minigames because there weren't any rules against it... is that legal? is it valid? I realize I should've checked pre-submitting but I can remove the run and try again if it's not...

There was a rule that stated you have to put it on all minigames for Duel Battle, but I just saw that it was changed. I think your run is fine.

so in the future am I still allowed to do simple minigames? I checked before my run and saw no rules for or against it

Yeah you are allowed to.

Yeah that's totally fine. Just as long as no handicaps are changed.