If you right click the fractalize button there's an option to convert Straight to Smooth. You can go back and forth with it. You might want to fractalise it just a bit more right now before going smooth as that will give it a more wiggly appearance. Don't go overboard, though. No more than 3 hits with the fractalize tool at it's default setting. Then go smooth and see what you think.

Save a copy first ;)

The problem with your original file was a corrupted sheet. I also got an out of memory warning the first time I tried it. Then I discovered there was a problem with the SYMBOLS sheet and created a new one. Once I copied everything across and deleted the original SYMBOLS sheet everything worked ok.

Your system has plenty of memory and should cope ok with 40 million PPP on export. How does it do with the repaired map?

Great to see its working now :)

I was thinking about how long this rendering might be taking you, since you had time to write a comment while it was rendering.

Have you set your Maximum Pixels Per Pass to 40 million yet?

The default is 4 million, which can cause CC3+ to do many passes over the map for a full render. Unless you have an old machine it might be less time consuming to increase it to 40 million.

Type EXPORTSETMPPP on your keyboard and hit enter, then check the number of zeros after the 4 in the command line. If it's only 6 zeros type 40000000 and hit enter. That should greatly decrease the amount of time it takes to render your maps.

If you will only be playing in that region for a while I'd do a regional map and be working on a separate world map in the background while they're busy fighting for their lives in the first region.

Then when they get to the edge of that first region I would do a third map of the region they are moving into, based on the layout of the world map.

If you want any particular sheet to be unaffected by the lighting it needs to be above the sheet with the Wall Shadow, Point Light Finalize effect on it. Then you can control how that sheet appears the normal way using colour adjusting sheet effects like Colorize, or Adjust Hue/Saturation.

When I say 'above' I mean as you are looking at the map. In the actual Sheets and Effects dialog that would be below it in the list.