Many hours with Falko's world editor made it possible
Have you tried Volutar's? To me it's easier with it but it's just a personal preference
Yes, I gave countries the same name as the sietch and in parentheses the region name.
The problem is that there are no extra labels for regions possible. In normal Xcom it is not a problem, because everybody recognizes the regions "Africa" or "Australia" immediatly. But regions like "funeral plane" are not identifyable on the desert plane without label. So using the charts on enemy activity would be very difficult without region names.
A more detailed planet with more countries would be good indeed. I also like the special mission like in the "Area 51" mod.
Last night I spent some time listening to the music (great selection btw, it's very hypnotic) and looking at the globe, trying to come up with an easier solution. Even ended up looking at maps of Arrakis and actually realized that I'd have designed the landforms in a different way since I imagined them differently. But the core issue behind all of this is what you can do with the OXC engine vs. the Dune universe, and starting from the top, there's the storyline which affects things like the cities, missions, etc. So here's a few ideas I had last night that might be interesting or not
* Carthag, Arrakeen and any other cities would be marked but only used for special missions (assassinate Harkonnen Leader, steal spice, etc.)
* Sietches would be countries, but the actual location of the sietch would not be displayed on the map since Fremen are nomadic people, so they have several locations where to set camp and they like to keep those locations a secret, even from other sietches, for security reasons. Terror missions could take place in different locations
* Are you thinking of adding Atreides? Now that armed civilians are possible, you could set them as a 3rd party during a battle, although they will shoot at your units during reaction fire (but not while the AI is moving them)
* If Atreides (and Paul) aren't added, you could also add a 'Lisan al-Gaib' or 'Kwisatz Haderach' unit for the Fremen that to create it would require retrieving Water of Life. The Fremen already had that prophecy implanted by the Bene Gesserit, and it would make sense for one of their leaders to play the religious crusade card by researching the Missionary Protectiva. And actually you could give the whole mod a more 'messianic' or superstitious tone in the text used for UFOPedia, etc.
* Bases could simply be Harkonnen outposts in the desert (actually, better on rock, otherwise worms would eat them). Then Harkonnen could get bigger bases as time went by
I'll stop here. I hope this is useful