Very few places in WDW do not take CC or room charges. You may find a popcorn cart or other snack vendor that cannot take the cards, but for the most part all take CC's.
All the CS places DO take credit card when not on the dining plan thats always how I pay..The only places that do NOT are Some of the carts that sell ice cream and things like that...
I'm specifically interested in WHO DOES NOT TAKE DEBIT CARDS? Can I buy a Mickey Bar with my debit card? Or a turkey leg?
I don't think we can charge things at the Parks to our room key - we're staying at the Swan. I think we can charge anything at the Swan or Dolphin to our room key, just not anywhere else.
LSUmom4kids - I don't know about locations that do or do not take debit cards (although I do know that the hot dog stand at the Boardwalk will not let you charge to your room), but you are correct about not being able to charge to your room at the parks when staying at the Swan. I've stayed there a couple of times and I have to say that was one perk I missed.