I'm about to move to Paris. I've been a LH SEN for ever, but I guess I may be using AF now a lot from CDG for long haul. I have a Delta account (with the original card from 1988), so I'm not sure if I should switch to using my SkyMiles account, get a brand new Flying Blue account, or... and this is the main *A question - should I carry on flying LH etc as much as possible to keep the *G?