Are you a strictly leisure traveller, or do you travel for work sometimes? If you do travel for work, your employer's travel policy may have a say in what frequent flyer/stay programs you should end up joining. For example, my employer prefers Delta and Hyatt, so I am a member of Delta SkyMiles and Hyatt Gold Passport. In addition, Delta operates more flights out of my home airport than anyone else, so that plays into my decisions too.

Not sure I can comment on cards - but you may want to do some reading on some of the many blogs about doing Disney on the cheap.