1. It is controlled by the
ECU.
2. It can be adjusted via a reflash. It is not adjusted by peak and gain like a electronic boost controller. It is adjusted by directly controlling the duty cycle of the boost solenoid.
3. 9psi
4. Safety is found in the tune not the amount of boost you are running... to a point. You can piss in 20psi.
5. pink top feeds = 565cc @ OEM fuel pressure. They wont hold you back on the stock vf35. But consider upgrading the standard fuel pump. Good cheap insurance. These injectors can also be decapped up to 816cc
6. Forged pistons can be found in all 2002-2005 STI EJ207 motors. That would be a yes in your model. I think OEM compression ratio is 8.5:1 or 8.7:1. CBF Googling it.