Never transfer rewards points until you are ready to use them, unless there is a transfer promotion. (And Chase has yet to have any.) While airlines will often make changes without notice (i.e. "As of this morning we increased our baggage fees), it would be quite unusual for a transfer partner to annouce "As of today, you can no longer transfer to Backstreet Airlines."

Keep in mind that whatever airline you travel on, your redemption is governed by the airline whose miles you use. So if you use USAir miles to travel on United, you are governed by USAir's rules. Most particularly, note that USAir does not allow one-way tickets (well, they do, but they charge the same as round-trip) and that is also true of Delta.

Is your fiance getting cards to get signup miles? If not, perhaps she should.

I'll also add that for hotels, Priceline's "Name Your Own Price" if used effectively can get you pretty good deals. If you're looking for a boutique hotel or something really high-end for a honeymoon, that might be a little tougher to find, and also some international destinations have a limited selection. But if you just want a Marriott/Hilton/Westin in the USA, you can save some fairly significant bucks.