A few answers here in the early stages of the flight:
Channel 9: Yes
Air nozzles: Yes
Foot wells appear the same width at the front for all non-bulkhead seats but remain square for the straight seats and taper on the angled ones. Bulkhead are definitely wider.
Power and IFE controls/headphone jack move depending on the seat but easily accessible. Never up and behind in the "tower of power."
Yes, there is a gap where you can lose stuff in the seats. Not really sure how that wouldn't be the case given that the seat moves within the shell.
More to come...