I think you can add it up to 5 days prior to your pkg stay. If
free dining comes out, you can change to that offering and it will be added to your pkg, your room rate will go up to rack rate - those are the parameters. You don't currently have to have the DP to change to the Free dining special.
Yes, Hoop de doo is prepay, we do it every time, we love it, but if you need to cancel, you can at least 24-48 hrs ahead, I think, and they will credit it back. We had to pick those tickets up at the resort ahead of our dinner, if I'm not mistaken.