I'm so glad this thread is here!!! I live in Boston but I'm starting university in Sydney in February. I'll have AAdvantage Gold by the end of this year. Getting to Sydney, though, I'm not sure if it's best for my to stick with AAdvantage or try something new.

(1) What is most important to you in a FFP?
Upgrades are probably most important, but I also love lounge access and priority boarding/check-in.
(2) How many miles do you usually fly each year & in what class? How many flights/sectors?
I'm planning on doing two round trips a year between BOS and SYD. That's around 40,000 miles total (with connections and class of service boosts I'm sure I could get that to 50,000/year). BOS-SYD is usually 2-3 sectors in each direction, so anywhere from 8-12 sectors total. I'm only considering flying premium economy (business sometimes) because I can't squeeze into economy for so long.
(3) What types of fares do you usually buy?
Nonrefundable premium economy and business.
(4) Can you choose your airlines and/or class of service? Do you travel for work and/or pleasure?
I can choose my airline. I am under no obligation to fly with any particular airline or alliance, I just choose OneWorld because I already use AAdvantage and Qantas is the best Australian Carrier in my opinion.
(5) Which routes and airlines do you fly most often?
US Transcon with American, Transpacific, I also have looked at Transatlantic with connections to the kangaroo route. Could also connect in UAE/Qatar, or via Johannesburg or Santiago. AA and Qantas will most likely be my most frequent airlines.
(6) What is your home airport?
BOS
(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?
I (will) have AAdvantage Gold for 2019, and have about 22,000 AAdvantage miles.
(8) Preferred Airlines? Most common Airlines flown on?
I prefer Qatar, BA, Qantas, AA, Cathay Pacific, Hawaiian and Fiji Airways (although those last two aren't officially OW members, AA does allow for mileage earning and redemption between the US and South Pacific). I have flown AA most commonly.

Thanks!