1.) Although I currently do not have ALL my runs terminated on wall plates, now that I think I have my speaker placement complete, I will be adding them for the speakers. I already have a plate for the cable TV, telephone, and ethernet runs to my HT system.
2.) My needs are very simple since I have all my components in the same area.
Audio = speaker
Video = coax
3.) Speaker runs would be first on my list. Since my room would not accommodate a 7.1 system, I would probably only need a plate with 4 speaker pairs (2 fronts, 2 rears) and then 4 single pair speaker plates. I guess I would consider an 8 pair and 4 double pairs, but I do not think I would bi-amp any of my speakers. Another wall plate that I would consider if you made one was a coax, RJ11, and an Ethernet switch (either 4 port of 8 port).
-Lou