If you are taking a lot of asian trips, your most logical bet is of course CX's Marco Polo Club tied into Asiamiles. Yes, accruing top tier is tough from scratch, but once in the Marco Polo Club, your chances of getting cleared waitlists are a lot better than most.

Qantas will start a new FF scheme in September where they will give 100% of the miles in economy class. Plus when you reach tier status with them, whenever you fly on QF designated flights, you'd bet a bonus of between 25-50%. Maybe you'd like to check that out.

To answer your question, if you have a Canadian address, yes you'd be able to accrue CX miles on most fares. But the moment you switch to an Australian address, you'd be subject to that country's rules on the AAdvantage program.