Why not have some xi fun? Nothing crazy but I like my wheels and dynavin, smoked lights etc. I remember this one 330xi at bimmercruise that looked pretty nuts, not sure what the extent was besides visual though.
In terms of usable performance upgrades, I agree with you though. I do think the OPs suspension/stance ideas are a bit radical... Keep in mind you're going to want to stick to a square wheel setup so you'll never get a really radical look IMO. That said, with nice wheels and a moderate drop (around the range of stock rwd e46, or a tad lower) your xi should be bearable
Edit-- didn't realize you had 7 series wheels on there.... I'm guessing they're staggered too?
Op, if you're looking for moar power, sell it and get a 330, m3, or modded e30/e36.