What do I do if I had someone else driving my car who did not have a license but I was the one arrested?

They have to prove that you were driving the vehicle while drunk. It sounds like they may have a problem with that at trial. Get a lawyer and fight.

You have a lot of questions. No, they cannot arrest you for refusing a roadside breathalyzer. Yes, they can offer you more than one field sobriety test and they often do. Usually they will have you do at least three with the breathalyzer being the last one. No one has to do them and you never, ever should attempt them. You will assuredly fail. The cop has one glaring piece of evidence that you were driving your admission! Yes, you could deny it at trial and say you were covering for your friend, but a lot, if not most juries, would have difficulty believing that. It would appear that you were lying on the stand to save your own skin. The rights you are referring to, I'm guessing, are your Miranda Rights. There is a lot of misconception about them thanks to television. They only have to read them to you while in police custody (under arrest, not free to leave) AND they wish to ask you incriminating questions. The first prong is where you will lose because the Supreme Court has held that most traffic stop encounters are brief detentions and not considered police custody for purposes of Miranda. Although, sometimes they can be. If there was a Miranda violation, the remedy is not to dismiss the case but to keep your incriminating statements out of evidence, meaning the prosecutor cannot use them at trial. There are also chemical test rights they have to be read to you at the police station before the give you an evidential chemical test such as a breath test or blood draw. That can lead to suppression of those results if they do not follow procedure. There is a lot that go into DUI cases such as the legality of the stop, administration of the filed sobriety test, and the calibration and maintenance of the breath machine, the certifications of the officer, and a whole host of administrative rules and procedures that must be followed. It is quite complex which is why you need an experienced DUI attorney on your side to help you fight the case and get the best possible outcome. Seek out such an attorney right away as DUIs have many long-lasting direct and collateral consequences that can impact your life and career for many years to come.

Lawyer up. Fight it. Not an easy case to win. But definitely winnable. Especially if your friend will testify.

You need an attorney and to stop making incriminating statements over the internet. Get an attorney now.