I couldn't make out your pics very well because they were too small and when I zoomed in they got pixelated. Looked like a scale model.
Both of my TV's are SUV's so to me, pinching the front is a waste of internal space. I recall an experienced builder pinching the nose slightly for the aero gain, and IIRC he said it wasn't worth the effort involved, but I don't recall who or which build it was. Rounding the front top above the TV height makes sense to me, as does keeping the front as close to the TV as possible w/o killing maneuverability or balance.
Keeping the cabin width about the same as the TV or less makes aero sense, too.
Can't really say about the foam sizes, except that big long unsupported edges in thin panels probably won't hold up too well. My walls are 1-1/2 foam with 5 mm ply inner skins. I went with laminated wooden edges in my galley area to protect against dents, maintain rigidity, and provide a consistent sealing surface. Until I put my upper galley shelf frames in and the counter edge rail, I could still flex the walls in or out by pressing on them; at least enough to slip those parts in. In fact, when I needed to get a little more overlap from my hatch inner skin, I trimmed these items a tad to help suck the walls in a bit. So you should either test or plan your interior structure (cabinets, stiffeners, whatever) accordingly. Not sure how you would do that for the roof part.
My opinion, if a lifting roof and foam construction are desired, I would take a closer look at how Sharon did her roof on
her 'My Away'. The partial roof panel and cofferdam lip go a long way toward stiffening and make it much easier to seal, IMO. Easier to build, too, I think.
Something very similar could be done with a curved profile like in your sketch.
Not to discourage you, but just some food for thought to address your expressed concerns.
