Originally Posted by
pinkn
I pay my own ticket with cash without redeeming miles but I'd like to collect the miles to be able to upgrade my family's tickets when needed
As I said, generally you can only upgrade tickets with that airlines miles/points. BA avios can be used to upgrade BA flights and full fare AA/IB tickets only for example. If you want to upgrade Emirates tickets, you will need Emirates miles.
Rather than trying to upgrade flights, you could just buy award flights in a higher class.
Originally Posted by
pinkn
My local Citi bank credit card lets me transfer my miles to the following airlines: Delta, BA, Qatar, Singapore Airlines, Thai Airways, Etihad and Asia Miles.
What would be the best way to accumulate miles into a one world airline? Obviously my Emirates Skyward miles can't be transferred, it's clear but when I'm flying with someone else, say with Qatar, Cathay Pacific or BA then which FF number should I enter?
You really need to look at each program, how often you use each airline and what your comparative earn would be, and how you want to redeem miles. Also note that depending on the class you fly, crediting to a different program may earn very little.
They are all different programs with different pros/cons.
Originally Posted by
pinkn
The downside is if I'm flying Qatar with my BA ff number I will get relatively low number of miles because I'm only a basic member in one world
You would be a 'basic' member of BA. You can't be a member of oneworld. Also the earn rate for Qatar flights credited to BA depends only on the class, not your BA status. If you are flying discount economy the earn rate can be 25% for deep discount economy.