1995 Park Avenue --- burned computer(?) under driver's seat

I have surmised that it is the "memory seat module" (MSM) and that its failure to function explains all the problems I mention above.

Now I am left with the question of why it went bad and came rather close to burning up the car.

The previous owner was of the 'larger' variety and crushed it?

I thought of that too.

On the outboard side of the lower part of the seat is a chrome module having switches for the recline function and the seat heater. The outboard edge of that lower part does seem a little crushed as if someone crushed it by standing or sitting heavily on the edge of the seat. So I thought maybe some wires got pinched or a connector got broken or disconnected. With the seat removed, however, I can look at the connectors, and it seems they are rather well protected by a movable steel cage or frame. Still I won't claim that the problem wasn't due to some kind of damage as you suggest.

I have cut the wires going to the MSM and am able to "hotwire" the motors so as to adjust the seat, although rather unhandily. Still I am unable to adjust the side-view mirrors.

I probably erred in my earlier post when saying that the burned MSM explains the non-functioning driver's-seat heater. The seat heater doesn't seem to be connected to the MSM.