RE: how long to keep the cards:
Both my business and personal AA cards came due last month. Citi's retention dep't. currently has an offer to waive annual fee on existing personal card customers for a certain spend level over a period of months (like $500 over 6 months). The best business offer I could get out of them was $5k over 4 months. No idea what it will be like next year.
I don't think you have to worry about them re-figuring lifetime gold, I won't come close for at least a year, and they'll wait 'til i get to 999,000 lifetime miles or so to make the change.
