The rims are most likely killing your acceleration and braking. I'd get some 16's with the widest rubber you can fit. I think the max without fender mods is a 225. With fender rolling and playing with offset you could fit 245's from what I've read here. R-comps would be the isht though. You are doing the right thing in learning your car though. Once you have it's feel down you can step up to better rubber and make them cry.

Do the school though. It will amaze you how much better of a driver you will become. I know many of the Evo school instructors and believe you me, they'll help you more than any car-mod you can do.
Dave