I was told check in was at 4 and out at 10 a few weeks ago. We were able to come in early due to our circumstances of being there (Car accident) and they also allowed us late check out which for us was 11:30. They are great to work with so ask for what you need!
The beach is free but often times you do have to pay for the professional beach chair/umbrella rentals. It just depends on whether or not that's part of your rental package or not. You're always welcome to use your own chair and umbrella on the beach if you don't want to rent one if its not part of your package.