When it comes to symbol sizes, I think an important part of a map is that information is legible when zoomed out. Exactly how large that is depends on the map obviously, but in most cases, it will mean the symbols will be covering more area than the settlement actually takes up.

Currently, the settlement symbols do look a bit small IMHO. They don't have to be scale 1, but I think they could probably be 0.5.

More "precision" is usually better done by making a new local map from parts of the main map, which can show more details, and "more correct" settlement scaling. Exactly where the cutoff point for detail level lies between those maps of course differ based on the map itself.

You can however make a drawing tool that emulates one of the basic tools. Just set it with the desired shape, and then set all properties of the tool to use "current properties". This will make it act just like a basic tool, but it will have the options like trace (provided the shape picked for the drawing tool supports it).

As have been pointed out above, this starts to happen because your entities have too many nodes. But I want to point out the reason why this happens in the first place, namely too much fractalization. When you draw fractalized entities, CC3+ places intermediate nodes to be able to make this fractal shape, and each level of fractalization doubles the amount of nodes. This quickly gets out of hand if your setting is too high. When you draw large landmasses, it is adviced to use a lower level of fracatlization. This can be reduced using SIMPLYFY as mentioned above, but it is probably best to draw with less fractalization in the first place.

Since those above didn't answer this, yes, this is how it works. You can make commercial maps out of the box with the standard license. and those maps can be utilizing any of the assets distributed with the program. Note that this is limited to publishing the maps you make with said assets commercially, you're not allowed to distribute the assets themselves. But please use the contact details provided by Sue above if you need official clarification, as most people here can only give you an unofficial answer.

There are no specific assets for this kind of map that I am aware of.

There are some extra textures and symbols for Cosmographer through the two HiSpace issues in the Annual Volume 6. None of them are exactly what you are asking for, but they do give some additional options, including worn, dirty and rusty stuff, which can make it easier to approach making the kind of maps you want. I find those textures very helpful when I don't want shiny new stuff.