Nice, good to hear you found some possible causes. If you have a logger though, I'd still log to make sure that the idle switch is working. I've seen plenty of idle sensors that have the wire hooked up, but still for whatever reason the ECU doesn't get the signal. So I'd still check that if you your logger can do that. Or just let the car idle and detach that wire and see if rpm's change based on whether or not that wire is hooked up.
Cliff note = wire hooked up to idle switch does not mean idle switch signal is good
