We chose, by design, to NOT "touch" anything in your plane, because it would lead to an all new sort of problems. And of course, GSX cannot take into account every different systems simulation for every 3rd party airplane out there.
A very simple example: on a plane the doors would open only if you have electrical working. On another plane (I think the MD11 works like that), you need hydraulics. Another 3rd party plane might just not care, and always let open doors. Another 3rd party airplane might become *seriously* confused if an external program would change the doors status, possibly losing the sync between its internal simulation and the door's status.
A big mess we decided not try to mess with. The simplest solution is the one that works best: let the user operate the doors, according to his own plane specifications and limitations.