No to both questions, Yes, i switched the mike, no bang yet. And no, my bluetooth does not beep regularly, only once on connecting to the phone and then it is silent. For the first issue i would try reseating the mike arm, switching it back and if that does not work contact Bose for repair.
For the second, that sounds like a connection issue, most probably from either the position of your phone relative to the headset or the phone itself. I keep my phone in the ashtray (formerly ashtray) behind the tiller.