SeenItAll
Ah the Curse of the modern aviation world, the unrealistic connection..I don't think you can blame AF or CDG, IMHO I wouldn't plan on making a 1 hour 30 connection at any airport anywhere in the World.
As for the flight then holding at the gate - I think Rainboe has given you a pretty good explanation, I'll only add that the US authorities require the passenger details to be finalised and passed to them before departure, so thats' perhaps another reason for the flight being "sealed".