mr44,
In response to #1, I'm guessing that the little holes aid in kydex retention. I.E. more points for the sheath to grab onto. Also, I think they look great. Different strokes for different folks...
In response to #2, and I mean this with absolutley no disrespect, have you carried a lot of different neck knives around? I, myself, have, and any weight that can be shaved off is a great idea in my opinion. I don't see what advantage full Micarta scales would offer besides satisfying your aesthetic preferences. No grip retention would be added, only weight.
Regarding a cord wrap, believe it or not that can add noticeable weight. Also, it would add thickness and I like a neck knife to be as flat as possible. You should experiment for yourself though. And speaking of sweaty chests, don't forget that a cord wrap will absorb your perspiration.
I agree with you, however, that the AUS-6 shouldn't be bead blasted :barf: