While it's probably a laudable goal to shoot for a time close to the local stock track record in a fairly stock car, there's always going to be someone else who comes along with an even faster time.
Those of us who track get better with experience and some get pretty good, but hardly any of us will ever develop the speed of a Leh Keen or a Michael Marsal, or even the speed of a top-level club racer. So we should just enjoy the track for what it is--a challenging, fun learning experience.
Enjoy your mods and don't feel guilty. Maybe do one at a time so you can appreciate the difference each makes. And with our cars, you probably get more utility out of suspension and brake upgrades than power increases.