Did they have to read me my rights? and what other illegal things did this cop do?

Unlike what pretty much every cop movie would have you believe, you only have to be read your Miranda rights before you are *interrogated,* not arrested. Even if you aren't read them, it would only mean that anything you said couldn't be used in court. Since you admittedly reeked of booze and a breathalyser proved you had been drinking, the cop had all the evidence he needed without you saying a word. The cop had probable cause to suspect you were all drinking both by the way you were acting and also by one person's admittance of drinking. Unless he was holding a gun to your head he did not force you to take a breathalyser test; you could have refused but you would have been brought in anyway as again he had probable cause. Sorry, but nothing this cop did was illegal, unlike you and your friends.