When we store the camper for more than a week, we wipe the fridge dry, and then loosely crumple a few sheets of newspaper and place on the shelves. Newspaper absorbs moisture, keeping it off the sides and racks. As long as we stick to this process, we've had no mold.
Always drain the fresh tanks. Stale water is an invitation to algae growth. Just be sure to replace the plug (or close the valve) on the drains. Mud daubers love those little holes.
Make sure propane tank valves are closed.
I had not heard of squirting dawn into the black tank. Will that not interfere with the enzymes? Interesting idea though...
Do NOT pull the pin on the emergency cable at the hitch. As someone said, it will drain the battery in no time, and won't help the brakes either.
Keep asking those questions....that's how we all learn from each other.
2016 Ford F-350 Lariat CC, 4x4 SRW. B&W turnover with extender. 2015 CC Silverback 29RE, fitted with Reese Goose Box. Amateur Extra Class K5TS, 2016 nights camped 16