From what you have shared, I think you have a fine setup to start with. My recommendation is to race it this year just as it sits. Take one aspect to work on per autocross weekend, but I don't think you need to change anything major. You may just need to practice driving it. Be sure to start slow on your first run, then on your last run, try to knock down every cone on the course. On that first run, be sure to get car slowed enough that you are off the brakes going into the turn. Try left foot braking. Try to turn the wheel once entering the corner, then try not to adjust it-that is what it means to "set" the car. If you are "driving" a lot thru a turn, your tires and weight balance never really get to work for you. If you are understeering sometimes and oversteering others, its not the car-its you. Once you get settled down, it will do one or the other. Try to be precise instead of fast. And you will start to feel in control. When I have a bad day, it is from entering corners too fast and you can't really recover the car from that. I think the only setup deficiency is camber plates. The rest is mostly driving.