Welcome to FT
Have a look here, including the linked threads in post 2,
http://www.flyertalk.com/forum/onewo...help-here.html
http://www.flyertalk.com/forum/infor...help-here.html
Even if crediting BA flights to the AA ffp, you do not need to book these flights through AA. Just add your AA ff number to BA reservation.
Emirates is a partner of Alaska Airlines, as is BA. So you can get AS miles for an eligible EK or BA flight. AS is a very good ffp. So 1 ffp could get miles from both BA & EK flights (subject to the ffp t&c's of booking class)