Hi,

I used to be loyal to AA when it was relatively easy to earn status with them. I also did a couple of challenges with them and that earned me two intercontinental business trips.
The last years I haven't been loyal to any airline, I did no longer believe that being loyal would result in meaningful benefits. But I will again start doing more longhaul trips and I want to give it another try. Many things have changed over the last years and I think this means I will need to focus on another program.

(1) What is most important to you in a FFP?
(upgrades on travel, priority services when flying the airline, extra baggage allowance, good award redemption rates, better award access, free - discounted lounge access, etc.)
Reply: Benefits like seat selection, the occasional upgrade, early boarding, perks that come with elite status. (I've got a priority pass so the lounge access is more or less taken care off although many lounges don't accept the pass when it's busy)
(2) How many miles do you usually fly each year & in what class? How many flights/sectors?
(<25000, 25000-50000, >50000 miles - <25, 25-50, >50 flights?)
Reply: 25-50K (close to 30K) These are the miles I fly, because I fly discount economy I usually only earn 25% of this
(3) What types of fares do you usually buy?
(First, Business, Premium economy, Economy, cheapest)
Reply: I usually fly discount economy, sometimes premium economy. (maybe I will do this more into the future) I have never booked Biz, only used miles to fly Biz
(4) Can you choose your airlines and/or class of service? Do you travel for work and/or pleasure?
Reply: I choose the airline and class of service, all travel is pleasure.
(5) Which routes and airlines do you fly most often?
(US Domestic, Transpacific, Kangaroo, in Asia etc)
Reply: Every year is different, I fly for pleasure and with the exception of Africa we like to explore all continents. Next year we are going to Ecuador, Japan, & probably also Vietnam. The year after it will be somewhere else.
(6) What is your home airport?
(SFO, SCL, London LHR, HKG, Singapore SIN etc.)
Reply: BRU, but when fares from DUS or AMS are significantly cheaper I fly from these airports.
(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?
(AA Executive Platinum, QF Gold, UA 1K, LAN Comodoro, etc)
Reply: Historically I still have some AA miles. I also have a whole pile of AmEx MR that I can convert into BA/IB of Finnair Miles. Then I also have a credit card where I earn Miles&More miles. (Star Alliance)
(8) Preferred Airlines? Most common Airlines flown on?
Reply: None really. I sometimes think about switching to LH because of my credit card and because Brussels Airlines is part of the LH group. Then again, it is so damn hard to earn status in that program that I think I should focus on another airline. I've read that it is easier to earn status with BA. (with a status run every once in a while)

From the research I already did:

Pro LH :
- Earning miles with my credit card
- Meilensnapchen (discount mileage awards)
- Brussels Airlines at my home airport as part of the LH group

Negatives LH :
- Looks hard to get status

Pro BA :
- Usually relatively good connections worldwide with an easy and short flight BRU-LHR
- Together with AA, IB and Finnair a good worldwide coverage from BRU
- As for as my research goes not that hard to earn status (I should simulate what my flights next year earn)

Negatives BA
- Pay for seat selection