1, Frames should be cleaned at the same time really.
2, No
3, No
4, Whatever your both happy with, your job sounds a slight pain and he's probably doing it that early as its the only good time to do it without having the public around.
You haven't really said what the issue is, is he leaving spots on the glass, frames not being done, certain area not being cleaned (like over a vent) etc. I suspect as you've said he's using a trolly then he is having to conserve water and not able to give the glass and frames a proper rinse. On the flip side your job sounds a pain in the ass and you would probably struggle to get someone else if you sack him off, also your in an area with probably heavy traffic so there not going to stay perfectly clean for long.