Can you tent camp with an rv at the rv sites?

Yes

Yes it is at the same charge as if you are an rv, the advantage is you have water and electricity to use. The tent sites are very nice, super big and do have water access but no electricity

Yes rv site allow you to have a tent along with your Rv

Shouldnt be an issue, they do have "sites" for both.

I'am not sure but I don't see why you couldn't . If you take your RV you should be able to put up a tent .