I am traveling BOS-MOW at the end of November, and am considering buying an AONE3 to get there BOS-LHR-DME, and a second AONE3 to get home DME-LHR-BOS (I won't be away for 10 days and I don't have time to travel transpacific on this trip). Of course this means my next trip will have to be transpacific in both directions. Here are my questions:

1. Where is the best place to purchase a RTW in MOW? Since I'll be traveling BA on the LHR-DME legs, does it make sense to just purchase it from BA at DME?

2. When I'm ready to travel the transpacific route, can I use my AONE3 to travel on CX's codeshares with SU on the HKG-SVO route? If the answer is no, is U.S.-HKG-LHR-DME my best bet?