ok, here is the ultimate answer to your questions:
1. Doing doors is not so complicated if you know how: put the texture on the door-brush, select one of the visible sides, press S, auto-align the texture(texturing->brush->fit), then delete the values horizontal and vertical shift.
this is because of the fact that the texture automaticly gets aligned from the origin brush that you put where the door's axis is.
if the doorknob is on the wrong side, you have to put a - (minus) in front of the horizontal stretch.
then do the same with the other visible side.
2. If you do not place a trigger-brush, you will have to "use" the door to open it. we (the old team) decided that every door has to be "used" to open. only saloon doors will open by itself (with trigger-brush). we wanted this to be consistent in all maps, so i think it would be cool if it was the same in the new maps