I am looking to fly a rtw trip with oneworld this summer and i had a couple of questions since i dont know mych about oneworld since i usually fly skyteam.
First of all this will be my route:
ARN-LHR-HKG-BKK-HKG-SFO-MIA-CCS-JFK-LHR-ARN in F and some parts in C.

I was wondering for the first leg i could also take the direct LHR-BKK with either BA or QF but think service on CX is much better then the other 2.
Also is it worth flying C class on MIA-CCS-JFK on AA since otherwise i just buy a economy class ticket for those legs saving me one continent.
What is the best program to credit the miles to since i wouldnt be flying oneworld much i am not looking for status or something just to maximize my miles for a reward ticket, i was thinking AY since they give you 3 times the miles for first class travel but i am not sure about their redemption policies.
Thank you very much in advance!