I have never seen a list of all the places that will or will not accept Disney gift cards because most likely it will change frequently. If you are staying onsite at a Disney owned resort you can use your magic band at the restaurants and shops to charge back to your room. You will need a credit card on file, but you can go to the front desk and use gift cards to pay off what you have charged to the room. Just make sure you stop by the front desk before you reach your room's charging limit or your credit card on file will be charged.
Some of the places and situations where you cannot use gift cards that I can think of: None of the restaurants and shops in the Swan & Dolphin will accept them except for the Disney operated gift shop in the lobby. Same inside Shades of Green. Not specific places, but in the parks any place that has credit card capabilities will accept the gift cards, but there are some walk around vendors (e.g. castmembers selling water and snacks walking through some of the queue lines) that are cash only. Most pressed penny machines are cash only. You cannot use a Disney gift card to purchase another Disney gift card.