[Oldsguy]

It sounds like you might have some intermittent switches. A common problem with power switches in the doors because all it takes is one time with the window down in a rain and they can get corrosion that only gets worse with time. Sounds like you have tried to eliminate the switch from the motor but in the case of the driver's window it could be either. I am not sure if the motor from a later model car would work, your best bet would be to physically compare them side by side and see if they are the same in appearance and part number. About the inside panels, that can be tough. I have never removed one from that year and model Olds. I understand your reluctance to just start ripping things out, almost universally the arm rest comes loose first with long screws that secure it to the inner door metal, then from there the panel/panels. There may be some screws or not. Usually along the bottom they use pop in friction retainers. Hopefully someone will respond with some first hand knowledge. Good luck.