I'm looking at booking LONE5 in the following manner: (using AAdvantage as earning program)

MIA-MAD-BCN-LHR-xHEL-BKK-SIN-HKG-NRT-SYD-xNRT-HNL-DFW-MIA
(x is a transit point only, no overnight).

This trip was booked to hit 15 segments by flying through OW hubs without breaking the rules. The questions are:

1) Would it be cheaper to start in YUL or elsewhere with roughly the same cities?

2) I was able to book D class SYD-NRT-HNL, which is the longest flight and most important to to me. Would that change stick? the price seemed to go up $800 or so.

I'm bummed about the last of EQM on CX in L class.

Thanks.