To cover a few points...

- Miles earned thru the card do not count for elite status. You need 25000 butt-in-seat miles to earn status annually. AA does currently offer lifetime gold status for 1 million miles earned thru any method; if you ever start charging really high volumes, that's good to remember.

- AA only plans (as of now) to remove the more-room-thru-coach on routes that have high percentages of leisure traffic. Most of the carribean, plus a few other routes. Business routes, as I'd guess most of the LAX flights are, will not be affected.

- Amex often offers 6 months or occasionally a year with no fee on the DL Amex card. If that's the deal you got, you should activate the card and use it once, even if you plan to replace it with the AA card. That way you will get whatever bonus miles your signup offer included (10,000 miles?).

- Miles on both AA and DL will not expire with any activity (not necessarily flying) in a 3 year period. This includes earning miles from your card, or even redemptions.

- I have both the AA card (visa) and DL card (amex). Typically I use the amex for gas and groceries and the visa for everything else. The amex offers double miles usually for one month a year, but it's darn near impossible to tell if those extra miles post or not. Carrying both is expensice, an extra $85/year fee, and I'll probably cancel my amex before the fee comes due again.