1. The rev limiter is after the redline, it is a fuel cutoff. The auto tranny knows to shift before then.
2. I believe window switches are around $80, but can be had for less if you find them used.
3. The zex kit needs timing retard for over a 55 shot, this is stated in the tuning sheet that comes with the kits, and is on zex's website. You must also use 91+ octane fuel. They say that the system works with a completely stock car...stock motor, fuel and ignition systems. You will need one step colder spark plugs gapped at .030", as well as retarding timing for over a 55 shot. Check your plugs after you make a pass on the nitrous to see how the car is running on the nitrous.
4. The autometer a/f gauges are not accurate at all, and should never be used to tune with.