DD = Daily Driver meaning its not going to a separate weekend or track car
Auto X = Autocross, events set up in parking lots with cones where people bring all sorts of cars to drive around and test their skills. It's a great way to learn to limits of your cars handling so you won't do something stupid later on by trying to push the car farther than it can go
BTW, go without the wing and HIDs. The HID topic is way overdone, but the general consensus is that HIDs do not belong in halogen (what your car has) housings. They generate too much glare, don't have the proper cut off, and blind everyone on the road. Look in the electrical forum for more information.
The WRX body panels do look great, but I don't think the front bumper will fit on your car. The '11 WRX has wider fenders so it won't fit, same with the rear bumper (I think). However, you can go for the more subtle 09' WRX body styling which still looks damn good.