You don't seem to have the Point Light Finalize effect at the end.

Does it look like this inside CC3+, or only on the exported image.

If the latter, try this

I also noticed that there doesn't seem to be a light source located in the torch in question, while the torch north for it, as well as the one on the south wall both have 2 light sources in each. (Use Dungeon - Lights -> Show light symbols to visually see their location)

I don't think there is a way changing symbol references using macros. But as a workaround, you can just explode the symbols in the drawing. In most cases, this won't make a visual difference, but the symbols are now just a collection of primitive entities which should react nicely to color changing commands. Obviously, they no longer will be regarded as symbols for commands operating on those, but that is usually not that big a problem.

Grids (and thin lines in general) are problematic when exported to an image.

The reason for this is that a grid line may be for example 1.7 pixels wide in the final export. Well, an image can only use whole pixels, so it will either be 1 pixel or 2 pixels wide. Some people may then think "easy, 1.7 obviously rounds up to 2, where is the problem?".

Well, the problem here is that if you round up all the grid lines, these pixels add up. If your map have 20 grid lines vertically, and each takes 0.3 pixels more than they should, then there are other parts of the map loosing out because there are 6 pixels that actually belong to other elements. (And while 6 pixels seems low, remember that everything in the image fights for space, it is just that the grid lines are more visible here, but the image sizing algorithm have to deal with everything).

Let us just for the sake of example try to export 5 touching parallel lines of different colors to a 8 pixel wide image. Evenly divided, each line should then be 1.6 pixels wide, right? But if we round it to 2 pixels, we really only have space for 4 lines, there won't be any pixels left for the last one. Obviously, rounding up isn't going to work. Rounding down? No, not really, with 1 pixel wide lines, we only fill the 5 first pixels of the 8 wide image, with 3 left over. The only possible way to do this is to make some lines 1 pixel wide, and others 2 pixels wide. So even if they were identical in CC3+, there are no way of doing that in the exported image as long as the export size doesn't happen to line up perfectly (For my 5 lines, both 5 pixels wide or 10 pixels wide would have worked perfectly). So this is really the problem the image exporter faces, and thus end up with different widths of the lines on the export. Image resizing algorithms tries to be as smart as possible to lessen this problem, but it is difficult to handle single thin lines.

Using a high level of anti-aliasing helps combat this, because it will merge the colors from nearby pixels, creating an illusion of lines and features that are not a full pixel wide.

With border, I assume you mean an outline and not a political border here. There are several way to accomplish this, but the quickest is usually just make a copy of the landmass using :CC2COPY: or using :CC2OUTLINE: and then just change the properties of the copy/outline to give it the appearance you want.

Another option is to use effects, throw an outer glow on it for example.

No. The ability to stick to the map border is a feature of the drawing tolls which the basic commands don't have. Of course, you can always make your own drawing tool by going to :CC2DRAWTOOLS: and set it up as you wish. It can be set up to use the current properties, so you can make it behave almost like a basic command, but with the added features of the more advanced drawing tools.

If they overlap completely, use the different selection modifiers like selecting by fill, color or layer. You'll find all the details for this in the editing chapter in the manual, or an even more detailed overview here: https://forum.profantasy.com/discussion/7404/command-of-the-week-selections-week-28

Note that if the entities are on different sheets or layers, you can just hide the appropriate sheets/layers so you only see the right one.