mamsboi, you ever heard of pistol pete? hes a great dribbler. I read his sports illustrated article on how his dad made him to crzy things. one of them is dribbling outside with cloth gloves on, the ones with no grip. that would help u the most. what would also help u is to stare at a fixed object like a tree or something and think its a defender, or ur coach. i know in middle school or highschool its hard for PGs to get the play from the coach while protecting the ball. just do the pistol pete drill and make sure u NEVER look down while ur dribbling. that will help u improve the most. the BEST thing u can do right now is go to video.google.com and look up "dribbling drills" theres a list of like 20 quality drills. pick the ones u like and make sure ur routine is a little diffrent everytime to mix make sure ur brain doesnt go into a rountine.
about the three point shooting. at this point in time, i would be working about mechanics, not heaving, like u said. when the highschool coaches come to watch u play in games and they see that ur using proper mechanics, they will right that down on a little note as a reminder so they know ur good when u come into highschool.