you don't wake up until 11 and wonder why you can't sleep till 3AM?
8 hours is good regardless of when those 8 hours occur. i find it optimal to go to bed shortly after dark (if possible) and rise shortly after dawn. when i was your age though i am sure my schedule was much more like yours. it really only started to change with a fulltime job and trying to get up early on weeekends for group rides. i wouldn't skimp on sleep, other than training it is probably the best thing you can do to get faster.
can't do better than a fulltime coach and a very supportive parent. just pay attention to the advice given and i am sure you'll be flying in no time!