Not sure of the answer to question #1. I think you should have at least one day off somewhere in the middle. Don't worry, they should tell you what the schedule is SUPPOSED to be when you get there. Of course that could change somewhat while you're there.

Question #2: going to a school like this for the first time, you might feel overwhelmed at first, don't worry, it's normal. Just do what they say, study what they tell you to study, and you'll be fine. Cooperate and graduate.

Question #3: not sure about this. Just ask them about it when you get there, if you want. I have 8900 hours now, have been a jet captain for years, and I think somehow I never got that high altitude endorsement. Wouldn't worry about it. The instructors there are all great guys/gals, they will be more than happy to answer your questions when you get there.