NMMarauder wrote:If life would stop getting in the way of me having fun, I might make more progress on my trailer.
I'd really like to hang out with a cabinet maker for a day and watch them work. I think that would be very educational.

Cabinetmakers don't usually build frames, and then skin them. The cabinet carcass is plywood, and is at least as strong as a 'stick' frame. There may be some glue blocks, and nailing strips, but that's about it (not counting shelf cleats).
Make a plywood box, and then add a prebuilt face frame.
Trailer looks great.
I would worry most about skinning the inside with 1/4 inch, and the bunk top with 3/4. Prepaint the insides of the galley FIRST.
(Edit - skinning the FRONT of the bunk, ie the inside...) you could use 1/8th ", just make sure the cooler won't move much. Also, I wouldn't glue n screw all of it down. Leave yourself,a,way to get in there later, perhaps.