Here is an idea of how I'm thinking of attaching my wall to the floor/frame. The floor is 1x2 frame sandwiched by 1/4 ply top and bottom. The wall is 1/2 ply sandwich by 1/8 ply inside and outside. The 1/2 ply will be cut creating voids for insulation/wiring. As you can see, the bottom 1/4 of the floor ply has a lip, sticks out about 1/2 on purpose so the wall can rest on it. The walls will then be screwed from the outside into the floor frame, gold arrow. The lip is about 1/2 inch wide because of the carriage bolt, if the bolt holes were further in (they can't, I don't have tabs) then I would have more room for the whole wall to rest on. I would move the 1x2 floor framing in some more but I can only go so far before the carriage bolt has nothing to grab onto. The integrity of the wood will ot hold the closer I drill to the side edge of the 1x2. Now, the wall, when assembled, will measure 3/4 inch thick, BUT only a portion of that will actually rest on that lip and the rest will just hang out. I already bought the wood, so they can't be returned. Any thoughts?
This will be a light build, I'm not putting anything heavy on the roof like a RTT. I'm also counting on the galley wall, headboard, front roof spars to take the load as well.