Prior to the 1.9 update, the sounds I had were like yours Rickie, very low and almost unhearable.
I did however, have sounds from the ground crew, but now, only the captions at top of screen.
Since the update, no sound at all. GSX sound volume slider is at max, but to reduce FSX volume and up the volume of your audio system is counter productive,
as you may be able to hear GSX sounds, but it would throw out the balance of FSX sounds.
I think I may skip the deboarding/boarding procedure as it now becomes irrelevant. Pity about the ground crew audio though.
I tried to find your "sounds and vehicle movement" question Rickie, without success