Nice first post rant.
Hello. Welcome to the forum.
Yes, quality control sucks or is non-existent on these units. I had a long list of problems that were fixed in a few days while we lived in the unit. Time for a new, competent dealer?
You might be able to get the microwave repaired under manufacturer's warranty. My converter croaked 1 week before the manufacturer's 2 year warranty and WFCO provided a new one no problem.
My experience with Dutchmen is that if you log a warranty issue with them BEFORE the 1-year warranty is up, they will fix the issue.
BTW, I bought mine on a whim. I'm familiar with Dutchmen so my quality expectations were pretty low. On the whole, it's been better than expected.
My fuel gauge doesn't work but I don't care. I suspect it's wired incorrectly like your gage{sic}.