You seem to have made a mistake when you drew your lines. If you followed Sue's tutorial, all your lines should end in that point in the middle of the circle, but it looks like you have drawn them so each line goes through the center and out the other side.

So, when trimming them, you are not just removing the part inside the circle, but the part that sticks out the other side. So when you get halfway round the circle, you don't have any more lines to trim (there is just a white remainder there that will go away on the next screen refresh).

You need to ensure that your lines end in the middle. You can do that with the :CC2SPLIT: command, but it is probably easier to just redrawing them, after all with the circular array, that's just a few seconds.

When you place your tabs, try switching off snap (bottom right corner) before placing them, it might be snapping that interferes with the placement when placing along a diagonal.

The fold/cut lines commands should leave behind a visible line. Just for troubleshooting purposes, try drawing a longer line with these commands on a clear background. That should make them more visible, and a longer line lets you see if there are any issues with the line dashing that makes it invisible.

The dioramas guide do assume some familiarity with CC3+. For example, for step as you refer to, it skips telling you about hitting "Do It" after you are done making the selection since this is common behavior whenever you use a CC3+ command that requires a selection.

There isn't that much documentation on Dioramas 3 itself, mostly because almost every is done using regular CC3+ commands, Dioramas is mostly a set of specialized templates, textures, and symbols. There are a few special commands, like the tabs and stuff which is handled for the most part in the quick access guide.

I tried replicating your problem with not being able to put tabs on all sides, but I am unable to replicate that. Not sure what could be happening there.

Seems like an oversight if the quick start guide doesn't mention fold lines and cut lines, but there are buttons for both of these in the left hand toolbar set. They are just basic lines, without any special functionality.

As far as I can see, all the textures from the examples on the Dioramas product pages should be in the product, but which textures the program presents you with depends on which style you picked when starting your drawing (Bitmap A, Bitmap B, Vector, Pro) [You should use one of the first two], but keep in mind that the finished examples isn't just a texture on a surface, additional details have often been added by placing symbols, drawing things like beams, and adding shapes on top of them, the textures provided are the starting background.

The Tome of Ultimate Mapping goes further into Perspectives 3, but just as with the quick start guide, it does assume familiarity with CC3+, you'll quickly reach a block if you just try to read the Dioramas section. And of course, the Tome is a paid product, intended for users who wants a deeper dive into the software.

To save everyone's time, I'll just point out that I cannot accept maps that rely on custom artwork in the atlas. Details here.

Looks like your current map is in the basic CC3 dungeon style. That style doesn't have additional catalogs, as it is just a vary simple preview style for dungeons. All symbols are in the symbol catalog being loaded with the map, the one currently in your symbol catalog window.