Very nice.

Quote Originally Posted by minimal View Post
The next step is to make overlays for different data views:
  • Cities, splinter groups and trade routes
  • Resources and initial landing sites
  • Areas of Influence (political boundaries)


....

Currently: Deciding if I like the darker land style in the world map. Deciding if I need a different more 'tech' looking version of the same map. Making a 'blank' version of the same map so that I can do more bare bones looks for some things.
IMHO you could answer that sort of question much better if you had some of these data overlays. I.E. you could tell if it's too dark by seeing if it contrasted enough with your data layers.