(1) DL Status would probably be most meaningful in terms of IROPS, rebooking, reward availability, etc. I'm honestly not seeing much tangible during flight that would make a lot of difference beyond Complimentary Comfort +. SPG Crossover would be nice but that's likely not going to last any longer than SPG itself.

(2) I've been relatively happy flying AA with MVPG to date, but I'm worried the future diminished earnings may make this a hindrance when it comes to retaining status (unless it's on segments) as well as RDM earning.

(3) My redemptions are already almost completely on AA and DL and I maintain a pot of Skymiles from my SunTrust Skymiles Debit Card, though earnings there have been cut and I had shifted most of that spend to an AS BofA Visa.

(4) It would be fairly minimal and mostly relegated to lounge access for 1 or 2 trips per year.