Cd -- that sounds like a tough row to hoe.
As for my credentials, I live in an R-license park model (these last ten years) that is less than 256sq ft. and was built in 1962. It's probably been on the county tax rolls since then.
I got as far as the 'home office' part of the video. The door swing was wrong! And it looks horrible from the outside. If you build a big brick like that, knock the corners off and make a triangular skylight in each hole. Bringing light into the corners of the box will transform the interior.
Whatever you do for the next year and a half, don't take the trailer to property you control. Shipping containers are the future. Start out with one 20' container and add a second, placing it 16' 4" away and parallel. That will make the long and short sides in the Golden Ratio. Then get an American Steel barn, they're one layer of sheet metal, arched, folded and corrugated for strength. It should be a low arch and overhang the outside edges of the containers. A row of sklights down the center if they have them.