Thinking About Cabin Construction

Now that the boat is ready to be flipped, I'm thinking again about the cabin.  Here's the plan, in general, for the completed shantyboat.

I'd been giving some thought earlier to the cabin layout, but finally sat down and planned everything out using real measurement.

In clockwise order from top left:

1. Small galley with 2-burner stove and sink
2. Couch with resident dog and cat
3. Bucket shitter (entered from the aft deck)
4. Aft stairs
5. Lounge chair
6. Woodburning stove
7. Table / chairs
8. Fore stairs

Now lets get down to brass tacks:  Looking at wall construction.

This is the side wall, first a sketchy sketch, then a more accurate one.  Pretty simple really.

It took some thought to place the windows in a vertical position that felt right. The expected window position of the inside and the outside are kind of at odds since the floor of the cabin is dropped nearly two feet below the level of the deck. From the inside, I want the windows to be more or less at eye level and not too high. And from the outside, where the cabin appears to sit on the deck, I want the windows to be a little above the midpoint of the cabin.

I decided on slightly tall windows at 3 ft which resolves the issue to some degree.  Three foot or so from the floor inside and just above the midpoint of the cabin outside.

The original cabin plans call for 2x3 structural members turned parallel to the wall. I originally considered using perpendicular 2x4s in standard frame construction so I'd have natural nooks and crannies between the studs that would be easy to turn into storage.

So I'm kinda confounded on which method I should choose.  I'm trying to measure the pros and cons of each.

2x2 Wall Construction
Pro: Lighter Takes less space Less material Easy to connect	Con: Harder to diagonal brace No nooks between studs	Note: Recommended by pretty much everyone in the boat community, but feels flimsy to me.
2x4s Parallel with Wall
Pro: Takes up less space	Con: Heavier Harder to connect No nooks between studs Harder to diagonal brace	Note: Makes thinner walls and weirder window openings.
2x4s Perpendicular with Wall (standard framing)
Pro: Natural Nooks between studs Conventional technique Easy to connect	Con: Heavier Takes more space	Note: Standard construction, typical window framing, including sills.
2x3s Perpendicular with Wall (compromise)
Pro: Natural (smaller) Nooks Like conventional technique Easy to connect Lighter than full studs	Con: A little heaver than 2x2	Note: This might be a good compromise. Solid framing with reduced weight.

Hopefully, you'll weigh in with your expert and experienced opinion. Or maybe you'll weigh in with your totally inexperienced pet theory, that's fine too.

After we flip the boat and add the front and rear decks, we'll be coming up on building the cabin pretty quick here.