I like the rear entry designs for that added space at the rear, but, for me personally I'm not sure I like the idea of climbing into bed over the covers or pillows; I prefer to get into bed from the side. Still, I'm considering something similar for a potential 2nd build (if ever).
So just plywood with no additional stick framing, even in the roof? My first reaction is that 1/2 inch roof ply is overkill (assuming spars are used), and that it may still sag just from its own weight if unsupported (w/ no spars).
Alaska with no insulation? Building with simple ply walls does go quickly and there are a lot fewer things to engineer/design/buy/build, but it is a heavy way to go. Using thinner material and stick building affords the benefit of insulation with hardly any weight penalty, maybe even stronger and lighter at the same time. (Don't think that 3/4 ply will stop a bear, it won't. They can rip just about anything apart if they think there is food inside... good argument for no galley, but you have to think about other fragrant items, too, like your toothpaste and other toiletries, snack food, etc.)
My other thought is when I picture Alaska I picture vast areas of wilderness with few restaurants in between, unless you plan on staying near civilization the whole time for your meals, I would want at least some rudimentary form of preparing food for those in between times; even if it is just a cooler and a way to make a cheese sandwich, or heat a can of something.
All intended as constructive thoughts. Good luck with your build journey!