How do you “know” its tuned, however its tuned? PO saying so isnt good proof. Regardless we can take a look at it and see what can be done, bolt stuff on, etc, but I wont be tuning it.
This guy knows what hes talking about, from experience not hearsay. The +10hp isnt going to be night and day different, so its not exactly “worth it” to push the limits on a weak design. Freeing up the response is completely different. it will be more fun to drive, but not putting a great deal more stress on anything.
JUST DRIVE IT!!! Enjoy it for what it is, your not ever going to be the fastest WRX out there, and I bet you cant out drive the car as it sits now. So just focus on maintenance and enjoying it. Best advice anyone can give you, especially one who like making money off modding cars!!! :number1