There are a great many ways to defend a DUI case, even with field tests or breath tests. Because you refused both, you will need to have an attorney examine the circumstances leading up to the stop, as well as what the officer alleged he observed after the stop. Your attorney will also check for any dashboard or booking room video. Only after examining those and other details will an attorney be able to properly assess your case.
If your privileges are to drive to school and work then those are the only places you are allowed to drive. Sports and after-school activities are extra. If you need to drive to practice, you will need to ask your attorney to request those privileges from the court.
The MIranda warnings aren't required until a defendant or juvenile is taken into custody. However, depending on the circumstances of the conversation, it could be argued that the juvenile did not believe he was free to leave, and was therefore in custody. (After all, what kid thinks they're free to walk away from the cops?) You should speak with an attorney about the fine details of the case so that the attorney can make that determination.
As far as the parent not being present - by law,...
Yes it's legal. Once they have charged you the case is considered started and the Statute of Limitations is satisfied. You can't avoid prosecution by avoiding court. You will want to speak with an attorney because it's likely that you have a warrant from your failure to appear in 2007, and these circumstances could make a judge more likely to impose a harsher sentence.
Your Miranda rights only apply to statements you make while in custody. Contrary to what you see on TV, cops are not required to read them in order to arrest you.
Coincidentally, I just wrote up a more detailed answer to this very common question
Police officers do not need to read you your Miranda warnings before arresting you. The Miranda warnings are a protection of your 5th amendment right not to incriminate yourself. They are to be issued before law enforcement questions or interrogates you. If they do not, it still does not invalidate your arrest, but you may have grounds to prevent any statements made before receiving your Miranda warnings from being used in trial against you. Keep in mind that it only applies to police...