Caveat to the answers:
Used to be AA EXEC PLAT for the past 10 years. Given the revenue imposed
Home base is BCN. But have homes in MIA and PDP (Punta del Este, Uruguay). So travel often to the US and South America. Once in the US or South America do need short trips (US, EUROPE)
Pay for my own tickets (there are 2 of us plus GUIDE DOG).
Ability to transfer CC miles is also important currently AMEX PLAT and IBERIA Sendo (only for those places that will not accept AMEX).

(1) What is most important to you in a FFP?
Soft expiry, Link to Credit Card, lounge access, ability to redeem miles (must say 90% of the times in the past have been able to secure OW award tkts for the routes that was looking reason that do not want to jump ship to lets say SKYTEAM that is my next choice).
(2) How many miles do you usually fly each year & in what class? How many flights/sectors?
Managed to fly 100K on AA
(3) What types of fares do you usually buy?
Used to buy mostly cheap economy fares but gradually moved to mostly or mixed J W
(4) Can you choose your airlines and/or class of service? Do you travel for work and/or pleasure?
YES. Pleasure and Work
(5) Which routes and airlines do you fly most often?
BCN-US, BCN-MVD, BCN-ASIA (pleasure and biz)
(6) What is your home airport?
BCN
(7) Do you have FFP status of any kind in OW or other airline? What is it? Do you have any miles banked in a FFP?
Downgraded to gold on AA have some miles left
(8) Preferred Airlines? Most common Airlines flown on?
AA, IB, QR

Having said that my analysis has shown that AA will no longer suit me, seems that best bet is between BA and IB. One other reason to support that is the fact that this year my heavy travel will elapse into 2018 (my BA calendar year is MAY8).

Let me know if I have missed anything and thanks in advance.

Best, JC