Very detailed quality on your photos and descriptions! I am the same " can do anything guy"and only want it done right.
My 2014 is having tank leak issues and is under warranty but I'm so picky that all my issues I've had over year and a half I have fixed myself.
My tank is often full and towed this way due to off the grid camping. Noticed a dripping from tank area and suspected a issue. After crawling under I found three straps were loose, bolts had pulled threads out and were 1/2 inch out. My tank box is galvanized steel and now was buckled in the center. My guess was it was an installation era not the design. Out of 10 box to frame and 8 strap to frame bolts only 2/yes two couldn't be turned with your fingers. These two ,with a ratchet ,were checked and proved to be "good " with threads in tack. Who ever put the bolts in failed at his job and stripped them out(all but two) on installing them. Give them a power tool without limits and no instructions.... Some good , mores better! As a 35 year service manager and master tech I see this a lot. If my guy does this more than once after instructions ,I fire them.
After retreading to a 3/8 bolt and washer combo reinforcing the brackets to carry the load flat and not to bow the box with a sag in the middle. Straightening the box with 2 by 12 a jack and a hammer I put it all together for now.
With your pictures I have the confidence to remove and repair the tank now as soon as I get a break from using it. ( as well as now I've broken my back in two places and can't physically can't do at this moment) so how much was a new tank? Has anyone looked at getting a custom fab one to fit the box correctly so it doesn't bounce around in a box to big and break stuff? Heat your fill hose with a hair dryer for 2 minutes and the pipe compound softens and slides right off.
The Streaming Gantt's