I've had issues with our keyless pad when it gets wet, locking or unlocking on its own, but not the high pitched noise you mention. I don't think the panel out of the box is sealed very well, and you mentioned having stormy weather. Had mine replaced by BCS under warranty once, but the new one did the same darned thing. I'm presuming water gets inside and shorts contacts. I eventually asked BCS while I was in there to super seal it and they siliconed or Lexeled where the panel mounts to the coach and also where the numerals pad fits in its escutcheon. Haven't had a problem since. Make sure they seal the new one to the wall with plenty of sealant, and also the pad in it's mounting plate so no way can any moisture get inside the device.
My Beaver's bay locks have never seized on me, but the old Pace Arrow's frequently did, and so did the similar locks on the Beaver's engine hatch. I just used the red straw on a can of WD-40 or other penetrant/lube to squirt some in the lock and around the visible latch mechanism, and worked the key in it until it freed up. It is probably better to spray in special lock lube or even dry silicone which won't attract road dust inside the locks.
Joel