I was just looking at my neoprene socks, and they are sewn and glued. The thread is only noticable from the outside (ie. they aren't sewn from the inside and then turned inside out), and the inside seams are pushed tight and glued.
REALLY Looking forward to seeing this come together. I have a pair of 40 Below TR on order (I'm waiting impatiently) , and would love to make or see something lighter.
To get the pot boiling...I'll say that I envision a lower section (maybe just covering the ankle) made of neoprene and a nice high eVent gaiter attached. Personally, I wouldn't bother with a zipper or velcro (just slip them on) as I would put them on the morning and take them off at night - that's me though.
It would be nice if the sole was beefy enough to use without snowshoes for when snowshoes aren't needed - Not necessarily a bare trail, but through some snow. However, I realize this is not the goal. Oh yeah, make sure they only weigh 1 ounce for the pair ;)
OK, I'm getting carried away. Have fun on your project, keep us up to date and good luck!!