Well, didn't hear from anyone on this and decided to press on regardless.

Talked to Merlin @ St. Charles Isuzu and he said the motors and regulators fail far more often than the switches. So, since I had to take the door panel off the passenger side door in order to do the window spacing/guide lubing trick and fix that one from binding, I decided to do the following:

I dismantled the driver's side window and removed the glass, regulator and motor. Then, while I had the passenger side door panel off, I unplugged the passenger side motor from that and plugged the driver's side motor into it (Because I know that switch works). No reaction from the motor when I hit the switch, so I'm pretty sure at least the motor is bad. Have to put a new motor in to see if the switch is gone.

On a related issue, has anyone used motorcycle cable lube on the regulators? It looks like that would work pretty well.