Welcome to (posting on) FlyerTalk, handlebarmike!

Well, things always change.

So the one thing that I would mention is something has changed been your original post in December and your updated post now:

Southwest is thoroughly overhauling its program, and you will earn way fewer award trips start March 1 by flying them on cheap "Wanna Get Away" fares than you are now. So in cases where you've been flying them just for the FF program (on trips where you're connecting to DL anyway, like at LAX), you may want to rethink that. You should probably still use them where it makes much more sense connection-wise, given that you're in TUS, but you may not want to go out of your way to fly them when your main FFP has good flights too.

AA seems out of the picture for you, since it does not fly its own metal from LAX to anywhere in Asia yet other than NRT. And it doesn't even fly its own metal at all to Seoul for example (you'd have to connect in NRT to AA alliance partner JAL). Plus everything other Asia than NRT would require "backtracking" to either DFW or ORD. On AA you can use SWUs even on the cheapest fares, but only on its own metal, and you would have to fly 100k miles a year on AA and its partners (no EQM help from credit cards or partner promos like at DL!) to earn 8 one-way SWUs a year, and it doesn't sound like you can depend on flying that much every year. (And next level down, 50k flight miles a year, doesn't give you SWUs, you have to use miles + $$$ copay to upgrade, but once again you can upgrade from the cheapest fares.)

So that presumably leaves only DL vs UA/CO for you.

And I don't know enough about DL vs UA/CO to advise on that. And I'm really sure who does, as UA/CO haven't explained yet how their merged FFP will draw on UA vs CO!