How are you closing the IAC switch? It uses PWM, not an on/off switch.
As for the bleed screw (the allen head adjuster underneat a plastic plug), it is just a controlled air leak. The idle never changed a whole lot when I played with it but it would create a hanging idle when the engine was revved and allowed to fall back to idle. If you run it all the way in, the car should NOT stall. And you can generally run them out safely about 1.5 turns before a hanging idle crops up.
I prefer to adjust the idle with the stop screw, though some folks do not like to do it this way. It works well IMHO as long as you don't go way over the commanded idle.
Good luck.