It's quite simple. Just check the aircraft config sharing area.
Not at all. As explained, countless of times already, in the manual, in the forum, etc, the jetway operation is NOT related in ANY way to GSX! The work (or not) entirely independently from GSX and regardless if GSX is installed or not. Nothing in the GSX.config file will have any effect on the jetways.
The only thing that affects the jetways is the aircraft.cfg that comes with the airplane, which specifies the doors positions (the main one will get the jetway), and the AFCAD that comes with the scenery which specify how jetways are placed and which type is used.