Are all procedings at aa confidential?

Yes. The main reason aa has been so successful all these years is because of anonymity. Its like las vegas, what happens in aa's rooms, stays in aa's rooms. Though clearly better and often trying to undo what " vegas" has done:).
In theory. There is no legal protection - you could not sue or press charges against somebody who revealed your presence or what you said. There is also no legally recognized confidentiality as there is for doctors or clergy. However, the watchword is what is said at a meeting stays at the meeting.
AA. I agree with both dr wartenberg and dr. Blixt. Confidentiality is a basic tenet of aa. There is no 100% guarantee to confidentiality. That is where trust comes in.