To your question about cleaning the engine bay.
A lot of guys use Purple Power, Simple Green and the likes of those products. Heck, there were some detailing threads here just in the last 4 months.
Maybe a little search is in order with key words like "Detailing", "engine bay", etc.
Some scrub brushes, the cleaner and a garden hose aimed away from the alternator. Air tool for blowing out connectors and such when you are finished.
Bear in mind that any loose wiring jackets will allow water in, and the same for shoddy connectors so have an eye out for an possible headaches before hand.
If you are ready for autocross and the car is otherwise running properly, back burner the modifications for a bit.
Focus on the routine maintenance of fluids from front to back, just to be safe.
Then consider a proper suspension.
You will be way faster with a proper suspension and tire setup, then you will be with straight line power alone and no way to keep it planted/grounded.
Lots of suspension threads in the last while, have popped back near the top of each listing.
Welcome to the overly friendly, picky, and unadulteratedly awesome community that many of us call our VR4 home. /ubbthreads/images/graemlins/rofl.gif