I don't think I'm able to give you a complete process of what you should do but what I can tell you is to conceal a tape recorder on yourself before going any further with a lawsuit. You're going to need some real evicdence for something like this.
Well, in some cities it doesn't matter whether or not you yourself were drinking and you will still be issued an MIP or an MIA (Minor in Attendance). You should check the MIP laws for your area to get a better idea of what you're dealing with here.
If you don't appear in court and you ignore these tickets then if you are pulled over in these counties then you will be arrested as well as given jail time. If you take care of these in a judicial manner you should only recieve small amounts of jailtime and/or fines.
You were not in your vehicle so your license is not in any immediate danger. If this is your first offence and you're only 16 years old you will most likely get community service + probation. And if the police report says that you were as honest and cooperated as much as you say here, that will...
If they did not read you you're rights that isn't "illegal". It just means if you werent read your rights everything you said until you were read your rights will be thrown out in court by law.
Example: You told them you had a pound of marijuana at home, they could not bring that up in court...
It will be up to your probation officer whether or not you'll be taking drug tests. While on probation no matter what they always have the right to give you random drug tests.