Not even a plug here, but seriously one of my favorite recent cars in history especially a joy with it's incredible interior. We play with these all the time, and can't say enough about it. Congrats on the new ride and enjoy!
As for shifting, Perrin shift stop and brass bushings are all you need to really sharpen it up for sure.
https://www.maperformance.com/produc...rx-psp-inr-018
and
https://www.maperformance.com/produc...ce-psp-inr-016
There are short shifter options but I don't advise them since some are extreme and not as friendly for relaxed driving.
For power see below
https://www.maperformance.com/produc...-wrx-wrx-4g-s2