2001 Buick Park Avenue Temp control malfunction

This is a clean AZ car. Runs well but has several electrical issues that might be related:

1. Climate control- fan runs on low only, plus can't shift flow from dash vents to any other position. Indicator lights on control operaqte as normal, temp control seems to function. Removed dash control and installed in another car; works fine in all functions.

2. Auto-on headlights work, but driving into town they go off- work with manual switch. Once outside town they switch back to auto.

3. Shut off vehicle with radio on, exit vehicle, radio stays on for another 5-10 seconds.

4. Unlock door with key fob, driver's seat moves fully rearward. Programming through door memory buttons has no effect.

5. Faint buzzing sound in dashboard, constant but varies in volume.

Possibly unrelated- check engine light, 4 codes (3 evap). Car runs well except a misfire under heavt acceleration. Supercharger seems fine. Car runs excellent from light to moderate throttle pressure.

My very unscientific guess based on past experiences with other GMs of this era is a BCM issue. Where is it located, and will one from a 97 Park Ave that works perfect interchange?

Thank you in advance for your help!