Looking at a DONE 4 ex-CAI and needing to start westbound. Couple of questions:

A. If I don't want to burn my Europe/Middle Eastern stop or visit to start. I understand I must do CAI-DOH/AMM/CMN/LHR-USA/GRU with a <24hr transit in DOH/AMM/CMN/LHR?
Because If I try something like CAI-DOH-MAD-EZE I would have visited Europe and at the end backend of the RTW I'd only be able to transit through it on my way back to CAI (or whatever other ME final destination?)

C. If I end up doing CAI-DOH-MIA-EZE/GRU and the MIA is a transit under 24hr, would that mean I can then go up EZE/GRU-DFW and have 5 segments remaining for use within NA?
Or in case that MIA stop is over 24hrs would I have burned my NA segments and when I go back up EZE/GRU-DFW then that stop in DFW would have to be under 24hr before continuing to Asia/Australia?

Thanks for the clarifications.