The fluctuating idle may very well be related to the ICV. I would at the very least clean it and replace time-hardened hoses. Look for other vacuum leaks as well.
There's a very recent thread by "RonInSC" regarding the ICV. Here's a pointer to it:
Idle Control Valve hoses changed: 300 TE
The OVP gets blamed for everything imaginable. In my case I was dealing with the following situation:
After a lengthy drive(enough to get it good and warm), I'd pull over to do business somewhere and come back in 10-15 mins. Start car and drive off, but not for long. Car would die. Put it in park and restart. Most often the vehicle would restart and drive if I got back on the road and kept it at speed. If I came to another stop shortly after the restart, car would often times die again.
Replaced original single-fused OVP with revised dual-fused model. Problem solved.