You can't actually hide something that an effect is based on, because effects are calculated using changes from the below drawing, but there are a few things you can try to make it less visible.

• Set it up with a solid 10 fill. This is very transparent (if it is too transparent for the effect to work, try solid 20 or 30)
• Use the same color as in your effect, and add a little transparency to it.
• Make it pink and then use the color key effect to hide it. Color key must appear after glow in the effect list.

I find going with my own world so much more rewarding than those published worlds. It's more work on one side, but oh so much more flexibility on the other side, and the opportunities for a place the players can truly explore rather than read all about in a book.

Map looks quite fine to me. If anything, I think it might need some more settlements, but that can be a thing for detail maps. Since it had land et every edge, you can bet that the players will soon enough want to travel there and see what is beyond, so I hope you are prepared for that.

No, nothing should have moved, everything was kept the same, just in the data directory instead of the install directory to maintain compatibility with old maps. Sometimes the same fill are part of several add-ons though, and sometimes it's just the same name, but completely different fills. The name "Wall Cobble Grey" isn't particularly unique, lots of dungeon styles include grey cobble walls, but they still differ in style.

In this particular case, I guess it was distributed with both add-ons, because an owner of Perspectives 3 isn't guaranteed to have DD3. I have everything installed, and I have that file in both those locations.

Note that unless you actually edit the actual bitmaps to make your own variation of the originals, you shouldn't copy the official files to other folders. That's just going to put in into trouble the next time you are viewing the map on a new computer since you will also need to recreate your copied folders exactly as before as well, instead of just relying on the installer putting things right (and it will also prevent others opening the map properly if you ever give someone the map file.)

Check my recent blog article, it describes ways to fix Red X's.

Do note that moving the files to the installation directory is not really a good idea, the setup with the data files in a separate directory is for a good reason. Also, maps that uses the old relative paths (starting with # meaning installation directory) should also automatically be redirected to the data directory, so it may indicate that your map didn't use proper CC3 paths in the first place, so fixing the path sin the map is a better option for the future compared to moving the files, even though it may take more effort.