In the Citi AA thread there have been people talking about applying for the Visa & AMEX separately, and getting double the rewards (if they're approved for both). Also, somewhere in that thread, they said one should only apply for 2 Citi cards in one day (someone tried for 3 and was denied). My question is, what is the best way to maximize mileage here? The cards in consideration are:

Chase Sapphire Preferred (50k points)
Citi AA Amex (50k miles)
Citi AA Visa/MC (50k miles)
Citi ThankYou Premier (50k points)

Also, I have:

Chase BA Visa (received May 2011, 100k bonus)
Chase Continental (received July 2011, 50k bonus)
Citi Diamond Preferred (received May 2011...no miles received)

My husband is listed as an authorized user on all of these accounts, but I was the one who applied for them. I assume that he can apply for Chase & Citi and be a new user. I think I'd be able to apply for Citi, but I'm not sure about Chase. What do the FT experts think?