That's a bummer about the rear STB and the lower tie bar. Oh well, money I just saved I guess.
From the sound of it, I would guess one of your struts is bad. I've never heard anyone else relate a similar problem. I'm on an Open Track emailing list and recently someone brought up that some tuning company was putting various shocks/struts on the shock dyno just to compare numbers (Koni vs Bilstein vs Tokico, etc). Well, it turned out that as many as 30% of the pieces were out of tolerance brand new out of the box! I think you might have one of those 30%.
I'm afraid I don't have any clever suggestions for filling the holes left by the LEGACY badge. That definitely sucks. Maybe you could use the holes for an oil nozzle and a smoke screen nozzle for when you're trying to make a quick getaway from the coppers.
Sounds like you've got all sorts of cool stuff in the works. I look forward to seeing how the car turns out, in particular the grille and hood scoop.