The weird lines typically happens when you have nodes very close to each other making sharp turns (They're miter joins gone extreme). In many cases, this can be fixed by running the SIMPLIFY command on the polygon. This command automatically deletes nodes that are too close to each other based on the distance you give.

The DELNODEW command will appear in the future.

Great find.

As you point out, they will take a bit of work to get them into CC3+ format since he's presenting them as pages with many symbols on each. But, with the CC0 license, it do mean that it can be done by one person and shared/redistributed legally.

In this case, this is because you have created a map in the very limited CC3 Dungeon style. This is just a small preview of what dungeon styles can do, and can be used to create simple dungeons, but it doesn't include a cave tool, which is why the button can't find one.

I recommend trying another style, such as DD3 dungeon or one of the other dungeon styles available.

I also notice from the file name in the title bar that you have managed to save your file in the CC3+ installation directory under program files. Don't do that, it is a bad place to keep your maps. I recommend creating a folder inside your personal documents directory or similar.

This file doesn't change the defaults for new maps, it only allow the add city layers command to operate properly and add the layer to an existing map.

To change defaults for new maps, the only way is to edit the template they are based upon, but there is no global file to edit to apply to all new city maps, you need to edit the templates for each style individually.

Yea, this is one of the cases where you have to use Edge Fade and not Edge Fade, Inner. One of the differences between these effects is that edge processes each differently solid colored polygon individually, while edge fade, inner processes the entire combined shape on the sheet.

To use Edge Fade, Inner here, the borders would have to be on individual sheets where the number of sheets equal the N-color problem for your layout.