Not sure if instant hot was hardwired, or a switched outlet under the sink. If a switched outlet, could be useful.
Lower switch is a 12V
light switch for something, not sure what.
Beige switch, not sure, but a shot in the dark would be battery charge controller
Googling "RC Trace Engineering", I'm guessing that one controls a 12V-120V inverter.
Safe, not seen anyone mess with them but if the company still exists it's worth calling. Or a good locksmith can probably give it one look and pull a key out of a drawer that works. Should be easy to remove from the rv to avoid the service call charge.
Welcome to the forum!