Never is a very long time. I would wait on transferring my mileage out of those other airlines. Monitor expiration so you do not loose them, but you would be surprised how things in life change. Travel patterns, mergers, moving, job changes, program changes, etc all are very real events.

Choice of hotel programs is not to be taken lightly, but again, you can consentrate on one but do forget the value of a back up. Also the one you get your points in is the one you "must" spend them in.