I have ZERO experience with motorhomes but some with oddball vehicle problems:
The electrical issues might be a bad chassis ground. Check to see if you can find a braided metal strap from the engine to the frame or firewall, it might be loose or fixing to break. Also sometimes the ground is run through a motor mount which is impossible to see.
The stalling might be an auto-shut-off relay with dirty contact points. The relay will shut off fuel flow if it senses that the engine is not running but the fuel pump still is.
Just shots in the dark.