If we book our package though AAA, but shop our airfare and book it on our own, can we still use ME to get to the CR? Will AAA give us ME vouchers or would we get those from the airline?
The airline has NOTHING to do with DME. If you ask anyone at any airline anything about DME, they will hold the phone away from their ear and look at the phone with an expression on their face, a cross between thinking you're from outer space and smelling something really bad.
The only criteria for using DME is that you're named on a reservation at a WDW owned-and-operated resort, are traveling from MCO to that resort on your day of check-in, and traveling from that resort to MCO on your day of check-out.
Nothing else matters. Package or room-only, 1 night or 10 nights, booked through Disney or a
travel agent or Harry the Wonder Parrot, makes no difference.
If you use a travel agent, the travel agent will receive your DME documents, and then it's up to you to get them from the travel agent. Try to stay with me here ... DME is tied in with your WDW resort reservation, NOT your airfare. So, no matter how you bought your airfare, if you booked your resort reservation through a travel agent, then the DME documents go to the travel agent and not to you. They need to know that you need those documents (I had a TA who didn't understand that, and I had to keep explaining it to her, that I needed the vouchers and tags in my hand and not in her office file).