You picked a fairly legible font. An easy tweak to get the map even more legible would be to move labels off of competing linework. For instance, no reason not to move the word Vys up a few pixels, and Anarelis to the right. Places like Helonna, you could break the coast line, erasing it out from under the label. That will be hard up in the Collines de Jahlin, where you have a nice continuous area of symbols, but you could put a little bit of a glow of the background color around the labels for Elgaro, and Tordo.

Your scheme of sticking with one font and distinguishing type of feature by color makes sense. I'd shift any that are toward the light end, a bit darker, just for legibility.

See if it looks any sharper by using crisp circles instead of fuzzy ones, for the cities.

You might get the forest to match the mountains better just by very slightly blurring the trees. Color matters, true, but the level of sharpness might be enough to make them work better together.