Ok, I'm trying to think AA here (which is always dangerous because you must not use logic). In theory that would be only 2 D1s because you returned to your starting point on 9/29 which would "terminate" the first D1. The CLT-MIA leg would be another D1. However, I don't think the system allows "open jaw" flying--Fly Point A to Point B and layover for a day or two--unless it was a case of you were flying to DEN to connect to an AE flight up into the mountains to go skiing, and you got to DEN to discover that all AE flights to your destination were now overbooked for the next 2 days.
If this is hypothetical, and you are just trying to find another place where you think USAirways' system is/was superior to AA's sytem, I would say that you need to get out more. The system you now use is AA's. And, I don't care how much better the old system used to be. We used to run the DFW-LAX route with a wagon train, but times change.
If you are seriously considering this itinerary, I strongly recommend that you submit this example and your question to
[email protected]. If their response is it takes 2 D1s, I would print out that response and keep it with me the entire trip. Some gate agent or other non-rev somewhere on that trip is going to object to you going ahead of them in the standby line. (Just looking at it on the surface if it is one D1 for 9/15-9/29 flying, the 17th, 25th and 29th legs would all be D1Ts) If the system decides to charge you with 5 D1s, you are in trouble. The system does not prevent you from booking more D1 legs than your annual allotment allows. However, if you book more than 4 D1s the system will kick out a violation notice to the powers that be. Punishment can go from temporarily suspending your travel privileges (which would include your family and friends' travel) up to and including termination.
I know it's at least 2 because you can not return to your original starting point and continue on somewhere else on the same D1, D2, or D3.