I think if they did retheme the park like this it would make the park a premier attraction. i would like to see them break the park up into sections like Busch's hamlets. Each one would be named for a different Caribbean island. For example the terrible looking main plaza and surrounding area could be Port Royal, Jamaica. Each section would then look slightly different but the park would look well coordinated. The other cool thing about this is you could really make the connection with the European theme of BGW. France and Martinique, England and Jamaica, and maybe someday Spain and Puerto Rico. There are others of course too, but this would allow you to really market the parks together and they would actually FIT together! With all the islands in the Caribbean lots of expansion ideas too!
I know people will say we are not tropical enough to do Caribbean, but it is not all tropical. Some parts are even quite arid.
Water country has a great layout and infrastructure, so this would really all be cosmetic.