I am planning for the following schedule and appreciate your advises:

(Outbound)
AA8418 HKG-NRT (Operates by JL)
AA60 NRT-DFW (Operates by AA)
AA2324 DFW-MCO (Operates by AA)

(INBOUND)
AA1684 MCO-DFW (Operates by AA)
AA8481 DFW-NRT (Operates by JL)
AA8417 NRT-HKG (Operates by JL)

Questions:
1. Can the luggage be checked thru for HKG - MCO and v.v. MCO to HKG?
2. For outbound flight, where do I process the immigration at DFW or MCO? How about for the inbound flight?
3. The connection time for DFW-NRT is 80 minutes, will that be enough?

Thanks in advance.