Trying to make an RPG with an island setting

[meat]

I would focus on one location and some characters first and get it working. Sort of like a proof of concept. Once you got that one location working like how you want the final game to work like, with a character or two, then you can start expanding with different zones - and you'll have already know what kind of things to expect, so you can design your new zones with those knowledge in mind, which is _very_ useful. That's kind of like how big studio aaa games go anyway - they release a core game, then keeps working on it and slowly releasing expansion to new locations/content etc. ;)