Regarding your first point, I know what you mean. I am about 180lbs and just fit comfortably into the chair. I can imagine a wider person finding it too narrow.
I'm about 200 and 6"2, it's just ok for me, I have an incentive not to put on weight as it would get tight in there. if I have the throttle far enough forward it's more comfortable. If its back I find it a bit tight for the shoulders.
I only attach the keyboard tray if I'm going to do some skyrim or Arma2, but it can make it a bit cramped - I also have the table. In the keyboard tray slot on the right I normally put the shifter mount with my mouse may and mouse on top and rotate it in only after getting in.
