1997 Mitsubishi Diamante shifts hard

The best way to pinpoint your trans problem is to connect it to a scan unit. This will reveal any trouble codes in the shifting and help find the cause.
The "flickering" lights are usually caused by a malfunction in the alternator. You can usually check this by hooking a volt meter to the battery terminals. While the engine is running, turn on the lights, blower fan and electric defroster, if you have it, and watch the volt meter. You are looking for "spikes" in the meter reading. If belt is tight and spikes are present, I would replace the alternator.
On your "missing", you might want to do a good tuneup. Hope this helps.

You were still on the donor list, so I'd check to see how your car is doing.