Yes, depending on experience(type) you'd be a AMT(GA) or an AMT-T(Transport/Airline)
Last I heard of its status, it was shot down during the NPRM phase.
Yes, 3rd seat, you are correct, it died in the NPRM. And yes, all A&P's would be grandfathered. A&P's with a Ground Instructor license would have automatically recieved the AMTI license.