Clearly, something was needed to add further character to the swamps, and the first thing was slotting-in some lakes, ponds and smaller watercourses:

The new river lines were all kept deliberately the same size, and perhaps a little wider than necessary, to try to ensure they'd still be sufficiently visible after adding the vegetation. That latter was to be a mixture of mostly lower (lesser shadow), smaller, patches of greenery, including little-shadowed palm tree symbols to represent stands of swamp reeds, with a scatter of taller, = longer-shadowed, trees. This next shot shows the opening trial of this in the central hollow, although the sharp-eyed may also spot a couple of fresh structures have appeared in the northeastern woods as well, as I'd missed a couple of still-standing places there earlier, hidden among the chaos of my hand-scrawled base map:

Another two screenshots help indicate the general "vegetising" process over the top left swampy region, the first image with just the flattened-palm-tree "reeds", and the second with the remaining bushes and trees:

Two more images illustrate how the remaining regions were similarly filled-in, and how some vegetation scatter was added to the stream-lines linking between the edges of the swamps and woodlands:

I've left the swampland vegetation somewhat sparser on the right side of the map to give some space for possible other features to be added, as I hadn't firmly decided if some of the roads and tracks might be continued into it at this stage, or exactly what structures might be near those there already. Plus I also wanted to add some more stream lines at some stage later on (still haven't done those).

So far as I can recall, there isn't a specifically runic font available for use in the Community Atlas list (which includes most of the PF-provided fonts and those from a standard Windows 10 installation), although that isn't fully up-to-date, as it doesn't include fonts provided by ProFantasy in the Annuals from the last few years.

Your best option would be to find a suitable font online, either free or paid-for, depending on exactly what you need the font for, install it, and then use an exploded version of that if you're wanting to submit the map for the Atlas. The fact you can't edit it after exploding it is a disadvantage, although that really depends if it's meant to provide functional labelling (which someone else might wish to amend if they have access to the FCW file), or simply for decoration (such as in a map border frame).

I've not used GIMP in a long while, so my thoughts on its later versions are likely biased by the problems others have had with it - some of which may be down to user error, of course!

I'd only used MS Publisher (and a few earlier similar programs) for creating maps, graphs and diagrams prior to CC, and I'm not sure many would think of those as really art programs as such 😁.

I wouldn't worry about the length of the list of sheets here, Sue. You can't really design systems on the basis they might trip-up people fresh to the program, as it's more important they do the job well. If there's a concern their number could be intimidating, that's something which could be addressed usefully with a note or two in the PDF mapping guide for this issue.

GIMP's the only thing I've tried in this line, and haven't used that in a very long time (to create some symbols for use in the Atlas on this map there, as described in the opening post of this Forum topic from May '21). It has a learning curve worse than CC3+'s now (or so I gather from some who've battled with the newer versions of the program). I've only used the older versions, which were easier to learn - sort of...