My wife and I live in an Alu-Cab Canopy Camper on a 6ft bed Tacoma. You are correct, unfortunately they do not make an 8 ft version, though I know GFC does.
So far, ours is holding up incredibly well. We are both always near the truck, using it all day everyday. It hauls all of our stuff, and we both work remotely out of it 4 days a week. It is under constant assault by us.
I would certainly worry about mold if I put away the tent wet too often and for too long. When mine does get wet it gets aired out asap and for as long as possible. Sometimes this means opening it while in the grocery store, or when doing laundry at a laundromat. I have seen mold filled soft shells that got put away wet and forgot about for a week. I would not want to have to clean that out of my home.
Mine handles wind very well. IIRC we have peacefully slept through 40 mph wind, where the truck was rocking back and forth on the suspension, but the fabric stayed quiet. We make sure to tuck the zippers down low, where the mattress holds them in place, as they will jiggle if left towards the top of the windows.
The only thing I would change is just a bit more space between the edge of the bed platform and the end of the camper, i.e. make the top portion of the camper longer by 6 inches or so. That would help me fit a bit better through the pass through, but it isn't a large concern.
Definitely a plus one for sticking with your truck, although I am biased.
Any other questions let me know.
Edit after reading below: My setup was always intended to be an "I live outside, and my truck holds those things that I need in order to live my life" type of build. It was not meant to be something like a van, where I could live 'inside' at all times. I did not want that. I can certainly hunker down inside if needed, but that isn't the priority.
This makes it a lot harder, I think, to survive out of. I have no complaints, but it definitely can be something to complain about.