Reaching Galv has always seemed to be faster to me than reaching Balinda. When I go to galv's room, I can usually see alliance closing in (i.e. near the beginning of the little mountain). I have just about time to drop totems and pick a side before the first ones run in. Was always under the impression if I could see them, they should seen me too (whereas horde can't really see who went to balinda since the building blocks our view more or less). But it's not something I tested, more an impression and the fact that galv dies faster than balinda most of the time (about 10-15 seconds i'd say).

Balinda ain't hard, as said I can solo her with 5x elemental, with earth elementals and grounding totem on round robin. Wheres when I root a non tank in galvs room, galv will most likely finish that guy.

To answer your last question, besides some left overs, alliance troops have passed that point when we arrive.