Thanks for the very helpful response!
So I'm thinking I'll take the advice of the track guys and stick to a square setup. As much as I like the looks of the wide tires and deep concave wheels in the back, handling is more important to me than looks.
I'll read through the fitment link you posted; I trust that info on how much camber is needed to make 9" wheels and wide tires fit up front is in there.
In terms of camber for f30s, I haven't seen too many options yet... I guess lowering will add a few tenths of a degree, and I've read that there are oem replacement knuckles
that add 30min (-0.5deg). Would that be enough to fit a 9" wheel and a 255mm tire (or at least a 245) without any rubbing?