1) There are two holding tanks, black (poo) and grey (sink/shower). How do you know it's full? The indicator lights? They are often faulty due to residue on the sensor. If it really is full, go to
http://www.rvdumps.com/ to find a dump site near you. Google how to dump properly. Hopefully it hasn't been sitting for years or it might be hard and extremely difficult to get out. Always keep some water in the tank after dumping (several gallons) to keep things soft.
3) Some water heaters/furnaces have pilot lights, many have electronic ignition. Fridge doesn't. Just flip the switches and go. Remember to keep the trailer level, or the fridge will not cool properly (short term) and fail (long term).
4) Battery will run all the 12V systems. Lights, power jack (if you have one), slide. Anything that runs on 120V won't work. TV, A/C, cell phone charger etc.
5) I hear that it depends on the vehicle. I have no experience with this (never tested it out)
