I think you'll need a license so I'd check with the resort about that (if you rent the equip from the resort I think the license is included). Both of the locations I mentioned are on resort property so they will know. The pier should be fine at high tide but is pretty shallow at low tide - the other spots are deep water areas regardless what the tide is doing.
We've seen both dolphin and manatee in the waters around the resort including in the marina area itself weaving in and out around the docks and boats.
Enjoy!
Here are a few photos from our fishing excursions from the resort. Click for a larger view.

Bonnet head shark
]
"Blackbeard"

"Blackbeard" and "Scar"

Son-in-law with 48" redfish. (This one was too big to keep - catch-and-release only.)

Resort fishing pier.