Dude... This is sounding more and more like a coin toss. On one side you've got the benefit of not being 18 and (I'm guessing) first offense. But, then there's that laundry list of felony charges and the whole Drug Free Zone thing being that it was at school. Judges and law enforcement love being able to say they are "protecting our youth".
I would go out of my way to look and act as squeaky clean as you possibly can by the time this goes to trial. Haircut, decent single breasted suit, dump any jewelry other than a watch and perhaps class ring... and if you can pull it off... spend a little time going through a rehab program and hit a few NA meetings. Having a counselor or NA sponsor on the stand saying good things about you could go along way in your favor. Any ammo you can provide your lawyer to back up why they shouldn't lock you away and throw away, the better. Basically, try to look like them, act like them and do to yourself what you think they might do to you. If the DA thinks he sees remorse he may offer you some pre-trial diversion option. Have your lawyer ask about it.
You very well might get compassion because of your age. But, you might also get a judge that would look at some hard time as a way of making an example out of you for the rest of any perceived trouble makers out there.
Don't get me wrong, I'm all for bucking the system and thumbing my nose in the face of authority... But, at 17 I don't think now is when you want to make that stand. You messed up in a big way and I'm pretty sure you know that. Concentrate on convincing the judge and DA that you know that, get your ass out of this mess, give it some time, get out of your parents place and try again later if you would like.
I'll keep my fingers crossed that this turns out to be nothing more than an expensive lesson as to why you should never do something like that on school grounds.
