For those that read this thread, I thought I'd give an update. They finally listened to my plaintive pleas to take apart the console of my car and look at the wires that run along it, as I had read on this forum and another GP forum that this was a problem with 1997 Grand Prixs.
The BTSI wire from the shifter separated from the wiring harness and arced over to melt another wire into the wiring harness. Those two things are being replaced. We figured since the car was also stalling while the dashboard lights going haywire, we'd also replace the ignition switch. Right now, my car is still in the shop (going on a week now) getting repaired because GM is still trying to locate a shifter.
Edit to add: I intend to update in a month or so just to give everyone heads up if this resolves the problem.
