"So my question is, is the Idle Control Valve supposed to remain operated during the warm-up stage, and then release or what??? If I apply voltage to the ICV it clicks and fully opens."


I'm sure as heck no expert on this, but I just got through trying to diagnose one of these on my '86 560SL. If yours is similar in operation, read on. I thought the 'at rest' state of the ICV was wide open, that is, the little air port is fully exposed. On start-up, the idle control unit (behind dash on my car) ciruitry monitors the input from throttle position and coolant temperature, gradually closing the valve to slow the idle speed. So, a short 12V burst should energize the solenoid in the valve, closing it, not opening it. If you cleaned it, and it closes, it works.
Have you checked the idle control box/unit circuit? I resoldered the board on mine and it did help, but the part number that is on it is not the right one for my car, so I'm waiting for one I found on EBay to arrive.

__________________
1986 560SL
2002 Toyota Camry
1993 Lexus