I had an 02 STi and I was running -2°33' camber on the front with all stock struts, whiteline 'flatouts' and stock camber bolts. I think I had about -1° at the rear too.

Changing your sway bars to a 24mm option on the front and maybe a 22mm on the rear I think is the usual setup, would help, and then I'd look at strut braces, H-braces etc.

How do you mean you are struggling to get power down? How much power are you making, is the car mainly understeering?