You'll still run into all of the problems I ran into when I was looking into starting a Smithtown Bay fishing club except they will be on an even larger scale.
For starters, our population on the island is just to diverse. Too many people have too many opposing views on what a club should be about, who should be allowed to join, etc...
The second problem is liability. Nobody wants to be responsible for the actions of others (and I can't blame them). With a current LI fishing club on the receiving end of a lawsuit, it's understandable that people and sponsors will be hesitant.
The third problem was leadership. You'll find that only a very small percentage of those interested will be willing to volunteer their time. Finding leadership for individual chapters around the island will be tough.
Fourth, a common meeting place was an issue. We couldn't find one decent location here in one town for free. Finding locations all around the Island will be a challenge.
I can go on and on but I think you get the idea that this is something I and a few others spent a considerable amount of time researching. Yes it is true that many of our clubs are private and restrict their membership. However, if you post the locations where you fish I'll be glad to point you in the right direction to clubs that will take you in.
Let me know.