A: Some of the Downtown Disney merchants don't accept the Disney gift cards (like Wetzel's,) and also some of the cart merchants, like ice cream, popcorn and pretzels. (I think the carts may only be able to accept cash?) Otherwise, we were able to use ours at all of the table service and quick counter service restaurants, as well as nearly all of the Disney stores in the parks. Great way to save a little on our trip!
A: Yes, you can pay for just about anything in the Disney parks with this gift card.
A: Yes! https://www.disneygiftcard.com/ProductInformation/WhereToUse
A: Yes! And in the parks for food and merchandise.
A: Yes you can use this to pay for theme park tickets
A: Yes! You should be able to use these on the cruise. They can be added as a stateroom credit via the helpdesk when they get on the cruise. Or at the end of the cruise I beleive :)
A: There is no expiration date
A: Yes. You need to have a Disney Gift card account and you can combine gift cards up to $1,000.
A: You can use it anywhere in WDW as long as they accept Disney Gift Cards (so about 99% of places).
A: Yes, you do. They can be applied on the Disney website to pay for your entire trip.