All that Empire Era inspires everyone,I think ,to see more and more sea battles,doesn't it ?I would suggest a Mod that there will be 5 maybe 6 factions.
Each faction would have some islands/territories.
The main factions would be:
Great Britain
France
Spain
Dutch
Pirates and
Native tribes
The Campaign Map should be something like that:
http://shawnbrown.com/maps/caribbean.html
I'm not a modder !But this is just a suggestion !
Let the magic be made,by those who do it the best !!!