Wow! You got a lemon. We have 2017 Thor 35 sf and the only trouble was a screw got loose that holds one of the slide motors and caused it to hang up. As far as running the refrigerator, your alternator will keep the batteries charged going down the road. Shouldn’t have to run the generator. Batteries should last a couple of days running the refrigerator through the inverter. Run the generator a couple of hours every other day to recharge the batteries. We love our Thor.
We downsize from a 40 Ft American Eagle that we had for 15 years to a Thor Super C. The Eagle was nice and had plenty of room but I was getting stressed out driving it through congested traffic and we were starting to have many repair issues. We love the 2017 Thor Four Winds 35 SF. Had to get accustomed to less room and storage space and had to get rid of stuff that we had not used in years, just hauling around. The quality of the Thour is not as good as the Eagle but it has many up dated features the Eagle did not have. It is much easier to drive and the fuel mileage is much better at 9.5 per gallon. If I slowed down below 70 mph I am sure I could get 10mpg. We don’t regret the change. Hope you enjoy your Thor.