>>436757When I went through mine, I gutted it, stuffed 1" insulation between the skin on the outside and the wood panels on the inside, filling gaps with spray foam. Lot of work, but ... do it once, do it right.
There's an RV-specific tar-paper stuff for repairing leaks... sorta like peel-n-seal, but for RV applications.
Another alternative, though I'd recommend talking to some good foam guys, is spray foam. I researched that a bit with my trailer, found a bunch of companies that were more than willing to sell me a bunch of foam, but a couple told me I'd have better results with less work going with iso board instead. Might work for you though, if you've got some space to work with.
For power, how much are you actually using? Hook up to shore power and meter the loads. Oven, furnace, lights, fridge, whatever else you have in there. Give yourself at least 30% more power than your max. current and snag a decent generator. Inverters are nice, but $$.