I'm always delighted to help a fellow FT-er set on a downward spiral (or slippery slope as you put it). Want my opinon? You're overthinking it. Your last application was a year ago, your score is great, unless there are some other factors in play that we don't know, you can get any credit card(s) you want. Forget what Barclay or Chase told you a year ago.

Since you don't seem to have a firm understanding of what it is you want, have your fiancee sign up for the same 3 cards you do (if you want only 3, hint, hint). It can be a great strategy going into the future, too. And listen to MTDR; you really spend too much money on annual fees and in some cases delay the chance of re-applying for the same card and getting the bonus again.