In order to swim do need to have a room?

Yes...and you can show up early to wait by the pool for your room.

Yes

Actually now you can book a cabana to avoid renting a room, you just have to speak to the hotel manager to rent it. With it, it allows typically 4 to 8 guests! My brother has done this plenty of time, as long as there's availability

Yes you do..........

Aniyan Thomas yes