Here are my thoughts.
In terms of impassable barriers, I over-layed a skeleton over the map, and it just looks messy. I do however feel I have a solution. I can add fat deposits that would look similar to the fat that you get on the edge of a cut of beef. This way I can put the barriers on any edge and it will look good.
I do wonder if barriers are needed look at a map like "Conquer 4 Map". That has no barriers and it works.
In terms of the name for the Fly region. I am aware of the book "Lord of the Flies" and think it's a really cool name. Who wouldn't want to be the lord of the flies?
If possible I'd like to keep the name. Would I need to change it for legal reasons? As I understand the law I would be able to use it because it's a parody, but I'm no expert.
I am working on the XML code and wondered how much space do I need for the numbers? Foe example do I need to make space for a four digit number.
I will post a new version of the map soon.