Make sure that he is having fun......if HE wants to do more, fine, but take your clues from him. A freshman has a long ways to go so don't let anyone sap the joy out of the game by pushing that he should be throwing 80 or 85 or whatever, creating targets that will all depend on his physical development. And breaking balls can wait until that arm is older and more developed. A fastball and a changeup can work wonders, and no college is going to worry about how many strikeouts he had in 9th grade. Some kids hit eye-popping numbers early but there is no need to rush anything for a 9th grader. If he wants to play other sports, encourage that too-high school sports are a lot of fun creating a lifetime of memories and I hear of too many kids starting to "specialize" way too early. If he loves the game and loves playing, he will develop just fine.