You'd better go to him and tell him face to face, and he will definitely tell you to review well first, and then wait for the results of the preliminary test. Generally speaking, he won't promise you anything, because no one deserves the result of the initial test.
3. You are from our school, and you must have an advantage (if your teacher is not that hot and awesome). You just need to rest assured that you will do well in the initial exam and generally have no problem in the interview.