I'm not John Harper, but I've run the game; The sample island above is both. It's what's in the book for that island and is completely playable. The islands aren't "D&D adventures" with everything mapped out. They're starting situations+threats+possible final battle assistance. And as it turns out, they're pretty close to everything you need to run an Island. The rest of what you need is the GM procedure in the book, or something like it.