@civy Yes the camper is insulated, not sure about the floor though, but the floor has LVT which sort of acts like insulation to some degree (no pun intended). The A/C keeps it cool in 90+ degree weather, and I have heated it with a small 1500 watt marine electric heater in 20- degree weather with no issues, or a small Buddy heater has worked well when not plugged in to shore power. It's a pretty small space so it's easy to heat a cool.
I am not aware of any corrosion issues where steel meets aluminum. It's actually all aluminum other than the Dexter axle set up. There is no steel frame, even the floor is aluminum. The receiver that sits on the ball is steel (just the end piece), so that along with axles is the only steel on it. All of the aluminum is powder coated, except the bottom side of the floor which still looks like shiny aluminum that last time I looked under there. The torq flex axles will travel quite a bit offroad, but I would recommend the 4-way offroad hitch that TransGlobal Overland sells for it if you're going to do a lot of offroading. We just didn't take it offroad, although that's what it was made for. We planned an offroad trip to CO last year but had to cancel when we sold our house and bought a new one so we spent our vacation buying and selling a house. You might check with TransGlobalOverland for more info, he knows just about everything about this camper. He spec'd it and WeeRoll built it. If you would like to see it give me a call: three1four-six0two-00sevennine.