Well, I finally have the miles and I will be booking a oneworld award ticket shortly (Distance Zone 6
Total Trip Miles = 14,001 - 20,000 ). The iten roughly looks like this:

RDU-JFK-YYZ (AA)
YYZ-LHR (BA)
LHR-CAI (BA)
CAI-AMM (RJ)
AMM-DXB (RJ)
DXB-HKG (CP)
HKG-LAX (CP)

I would like to redeem for a business class ticket, and definitely have the miles, but wondered if I was able to just redeem for coach and use miles to upgrade on particularly long flights: YYZ-LHR, DXB-HKG, and HKG-LAX. Am I able to use AA miles to upgrade on other Oneworld carriers on a oneworld award ticket? If not, then a full business class oneworld award ticket will be the way to go, but I wondered if there was a way to save a few thousand miles...I understand that even if I could upgrade using miles for just those segments, it may be more mile expensive than the traditional business class oneworld award ticket.