This is the information I have received so far, hope it helps.
1. I was told the resort needs to know 3 months out the final head count. I am 5 months out now from my wedding so I cannot say how strict they are with that.
2. I have been told that there is no dance floor unless you get a DJ who will bring one in. I believe they can clear an area and you can use an iPod over their normal speakers but no dedicated speakers or floor that is just for dancing.
3. As far at the photographer goes, I believe it is implied that you will use their service unless you tell them otherwise. Not 100% sure on this one though.