So I've gone from 8 CEL codes to 3-4 down to 1 (or 2). Got rid of one code by switching the brake light connector with the 3/2-valve connector. Apparently I had them reversed and didn't realize it until it was pointed out to me that my reverse lights weren't there. That was an easy fix and was able to get rid of one code.
Went to Schucks and cleared the codes with their OBDII scanner and pinpointed the last code to one of the O2 sensors on the exhaust manifold. I have a new sensor coming in shortly and will have it installed with a new diff (bigger), and new M3 shock tower mounts (to increase caster).
Once all these things are sorted out I think the car is set... for at least a little while.