Which oneworld program shall I join?
 

I recently moved to England and will be traveling quite intensively on C to Houston TX, Singapore, Kuala Lumpur (on business) and to JFK/EWR on Y (leisure). So far I have bended cpy rules to fly BA/AA, however it's getting tougher.

Which FT program of oneworld shall I join??

AA. While BAEC is great for J/F flights, it is abysmal for Y, and it sounds like you aren't doing enough flying per year to reach top-tier status on multiple programs. So stick to AA trans-Atlantic and credit all the miles to AA. At the moment the earn/burn rate on AA vs. BAEC gives about 60% advantage to AA. BAEC is bad for earning miles but good for earning status and lets you game the system (e.g. YUP fares credit as F to BAEC and make earning status much easier).

Welcome to FT.

I agree with number_6, go with AA.

You can also enroll in the Platinum Challenge and get yourself Elite Status with very little flying (there are tons of threads with more info.) 1 LHR-KUL/SIN-LHR trip in WT+ on BA will get you elite status with AA.

Cheers

I dunno about AA...

...intensively on C to Houston TX...

Well, AA always requires a stop, whereas BA has good coverage n/s.

...Singapore, Kuala Lumpur (on business)...

SIN is a no-brainer; BA doesn't go to KUL, but one could get there easily enough from SIN on non-OW metal.

...JFK/EWR on Y (leisure)...

AA in Y is no picnic, and unless the OP would be traveling enough to make EXP upgrading on AA is not especially economical. Yes, with a Plat challenge the OP could make Plat (and probably stay there) but BAEC's MFU upgrades from (leisure, hence paid) Y to a comfier seat might make more sense. 2 1/2 RTs in J on BA to IAH and/or SIN would get BA Silver; if the OP then wanted to do a Plat challenge on any successive single RT to either place, he (I assume he - sorry if she) would get Plat, too. Renewing either would be up to ongoing travel commitments.

So I think BA to qualify, then AA for miles.

True; it is also important to note that MFU's on BA go only one class higher. So from paid Y (World Traveler) you can to go W or T (World Traveler Plus, aka premium economy). If you paid for W or T (WT+), you can upgrade Club World. The best value are the WT+ to CW MFUs.

I say you go with BA so that you won't be taking my award seats on AA transatlantic flights. :)

I say the reverse! :D