You have a very bunch of interesting questions. Just my opinion but I would forget trying to give them to your Dad. Nice thought but could mess up yours and his FF program unless you pay a fee. Second I would look at Alliances not individal airlines so you can earn miles on one airline from 10-15 partners. I would suggest going to the Alliance page and pick the one that would be most useful. I'm sure theirs others here that can steer you to the best one for you. Also no one I know of gives miles for past flights more than maybe 30 days ago, so I think you are out of luck on that one. You do fly enough to earn a free ticket every other year so don't give them back to the Airlines you paid for them with your ticket. Good luck and enjoy the family reunions.