There is nothing wrong with a n/a impreza. I ran an 01 2.5RS on the track before the WRX even came out. My upgrades were some JDM Bridgestone/Tokiko shocks, Tein medium race springs, 4 pot front brakes, H6 rear brakes, 140 pounds of weight saving and a bunch of wheels/tires to do street, snow, track. It was a great car and one that I wish I kept instead of buying the biggest pos, most unreliable, expensive, fall apart at EVERY track event 2000 Audi S4.
I know you have a newer N/A, and Subaru has upped the power for you, but added a LOT of road hugging weight. Something that I did was carefully look at everything on the car to determine if it could be cheaply (or free) replaced or reduced. Look at Lotus. They have never gone with power, yet compete rather well against big power Corvettes and Porsches in ALMS and Grand Am racing. The 140 pounds I lost was simple stuff like steel brackets that could be replaced with tie wraps and the various bricks within the car. You've got a good, reliable car which is going to go for a long time. Your mileage is better than a WRX and you can get 86 octane gas....if you can find it.
I have no problems with your car.