We are going to Punta Cana next week...advice please!?

Question

We are going to be staying at the Barcelo Cana Beach hotel. If anyone has stayed there...can you give us some tips? We are going all inclusive.

What are some of the good activities they offer?

What are some things we should avoid?

Where is a good place to swim with dolphins? I have heard some horrible reviews about some places down there, that have too small tanks and so on...

Did any of you get horribly sick from anything?

Thanks!