On the note of faction changing, I was thinking that it could be a really good way to help balance the nations out.
I.e. allow players to change faction into any other faction with less people in it.
For example.
Say we have 340 British, 190 Pirates, 135 French, 120 Spanish, and 80 Dutch.....
British players could join any other faction. French players could join the Spanish or the Dutch. The Spanish can only join the Dutch, and the Dutch have to stay their with their fingers in the levee.