#1 The Generator
I don't think your rig has a ready to use Generator compartment so hard wiring it is probably not the best choice. There are "dog bone" adapters available that will let you plug your RV shore line into the generator. Most of us who use generators that are not built into the trailer will site them a distance away for convenience and lowered sound. Also, a 3K won't power two air conditioners and the rest of the RV.
#3 The Keys.
You can get the CH751's for the compartments most anywhere. Just realize that we all have CH751 locks so most anyone can open your compartments. If you need security, change the locks.
For entry door keys:
http://www.fastecindustrial.com/products/default.html
Your key number should be stamped on the key.
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'11 Cougar 326MKS loaded with mods
'12 Ford F250 SuperCab 6.7 PowerStroke Diesel
Amateur Radio: KD2IAT (146.520)
GMRS: WQPG808 (462.675 TPL 141.3)