Welcome about chimbers. Lots of good reading you can do here, and lots of opinions to be gathered. Despite the differences in thoughts on some subjects, one thing is certain and that is that everyone loves their Escape.
1. An SUV with a 6 cylinder engine and a minimum of 4,500 lb towing capacity will work just fine pulling the 19.
2. They depreciate very little as the body being moulded fiberglass is very tough and will not really weaken at all, unlike stick built trailers. Getting your money out of using it a season or two would be easy when reselling.
3. You will see pitting on gravel roads. A coating like Line-X will stop this. If you were to opt for a front storage box I believe they are coated.
4. Depending on outside temperatures, amount of daylight, and use of additional appliances, I would say anywhere from 3 to 10 days.
-For starters, if you are going off grid the best thing you can do is to get the dual 6V batteries.
-I have been out for 4 days in mid-summer and had most of my capacity left, and I have been out for 4 days with temps dropping all 3 nights below freezing, and was well down in capacity, with not likely more than a day left. I don't have LED lights as yet either.
-The biggest draw on the batteries off grid depends on how much use the furnace gets, as the fan draws a fair bit of power.
-Keep the heat low (or off), throw on lots off blankets, and cuddle with your SO.
-Opting for the added insulation and dual glazed windows helps keep the heat in.
-Using LED lights will help save energy.
-Using a solar panel to top up the batteries will help too.
-You could also buy either a real small generator that will top up the batteries, or a 2,000+ kW one if you want to run everything including A/C.
5. Silly question. Go for it!!!!!