Coral Bay Villas and Belizean Shores are run by the same property management company so I doubt that you will be able to transfer to another resort.
We stayed at Coral Bay Villas in January and had a wonderful vacation. The condos are in a great location about a 15 minute beach walk south of town. They are very clean and the staff is wonderful. I'm fairly sure that you can use the pool at Belizean Shores if you are staying at Coral Bay but you should inquire just to be sure.
If you have any specific questions about Coral Bay Villas, you could always email Rafael at firstname.lastname@example.org . He was very helpful when we booked with them.
You may also want to do a search of this forum to see what others have said about Coral Bay. It may set your mind at ease.