Just a small question. Why did you put Pirates/Bandits and Tribes together? Both are very destinct and i have found myselve wondering how to explain why a tribe would build a floating city, etc. It´s not really critice, i´m just curious.
I originally had them separate, but the rolls ended up being very similar and decided to combine them into one. Also, combining them helped put all of that "neighbors develop" section onto one page.
For a little idea help, you could think of a tribe strapping together some rafts and building the town (like Lake-town from LOTR), and if you don't see them putting it in the sea then just use a river or lake.
Of course, you can always re-roll if it doesn't fit. I won't say anything :)