I have a Denon 4308 which does not let the 3D signal though so I've been contemplating switching it out--but not sure if just 3D add-on is worth it..
Anyway , I can answer question #1 and #2...
1. I have a Pany 110 and it will take any 3D disc and send it out checkerboard format to the Laservue--no conversion needed and it looks great! I believe the 210 adds Divx (who cares) and motorized door (who cares), while the 310 adds dual HDMI. The 110 is one of the best deals ever for a blu-ray since you can sell Avatar for almost as much as you pick up the unit (just over $100 or so). Even for me I have a Boxee for streaming (even lets you run 3D video through it) and my 1.3 Denon can pass the "lesser" checkerboard signal through...perfectly.
2. Mits 3D adapter: This is what you need if you hook in the PS3 cause Sony refuses to add a Checkerboard option (probably cause 3D on the LV blows the doors off any Sony display--but I digress...) I currently have my PS3 running through the adapter and straight to the TV since my receiver can't handle the frame-packed signal. You will also need this to do the same thing off your cable box. Luckily, since the A100 IS 1.4 HDMI (and I'm sure has dual HDMI out), run everything through that. Then since the adapter is known to do funky processing to ALL signals, run one HDMI out through the 3D adapter to the TV (3D input) and the other straight to the TV (2D input). Name accordingly and you should be set. FYI: Once you see MLB 11, Call of Duty, Crysis 2, Killzone 3 or Motorstorm in 3D on this size screen your priorities will change I do believe