You don't say what your annual mileage is (or will be). Sounds to me like AA status would be best for your international travel, but doesn't get you the good seating on B6. If you're flying to JFK on B6 then the extra legroom seats would be nice.

I think there's no right answer in your situation. Your quality of life will be better on B6 with Mosaic, but better for international with AA or AS. Personally if it were myself I'd deal with LAX and go with AA or AS status.