Good post - that all sounds very sensible ! One refinement you could try is to make sure the two spots closest to the DM are for quiet types. That would (hopefully) enable them to tell you what they are doing without the stronger types trying to dictate their moves to you.
How do you let people know which seat will be theirs ? Our group tends to just come in and sit down at whichever chair they fancy, first come, first choice....
RE: DND 5e: Rules for a Seven Player Table