each day you have two timeslots for actions: night and late night, these places (that allow you to up your skills) are available only at night (first slot) (of course if there is no client there)
There is no gallery and I don't think the animations change depending on what level you are.
If you just rest you will get the "double face somthing" ending, I assume if you max all your stats you will get one ending.
If you fail you get one ending
Last??