First off, welcome to the world of PhotoReading!
Secondly, don't ask any questions until you finish the course.
But, as long as you asked the questions...
1. You can PhotoRead the same book over again. You can activate the books anytime you like.
2. Yes. You'll increase your chances of experiencing "spontaneous activation." You only have to fully activate a couple books each week when you are PhotoReading 10 books a day.
3. Gaze, and be aware.