Originally Posted by
The Situation
There really isn't much value to being loyal to a particular airline if you are always going to be in paid international (assuming so for the TCON to SFO as well) since all of the benefits (i.e. lounge access, free luggage, priority lines) you would gain through status are already included in your ticket. I would say pick the flights that provide the best balance of timing, service, cost and amenities.
This.
Assuming international travel is paid in J, I would more or less decide to be a free agent. Pick whatever airlines and flights best suit your schedule, and collect miles on all three alliances. Maybe try for mid tier status in some programs if attainable.
But, if you must choose an alliance, I would go with UA/Star Alliance and try to get Global Services. I would fly on LH to FRA if it made sense.