If EGR valve is open too much at idle the engine will die. Disconnect the hose at the VSV going to the EGR system, this should turn off the EGR. Determine if this effects the idle.

When engine at idle, determine if the tube on the VSV where the above hose attaches to has vacuum. There should not be vacuum when engine at idle (valve closed). The EGR valve should be closed.

At to the ohm meter. Are you sure the ohm reading was zero ohms (short) or was it infinite ohms (a break in the circuit)?

When cleaning the IAC valve, spray the cleaning product into the rectangle hole on the bottom of the throttle body port just before the throttle plate with engine running. Spray a little at a time or the engine will die, keep it revving.

That's a lot of parts for such a small cost, good job!