First of all, I applaud the high contrast! It's very striking.

I don't know what the final physical size of this map will be. If it's poster-sized, then what I am about to say may not be an issue. A lot of the labels are difficult to read due to the interference created by the high-contrast lines around them. This is particularly bad in the mountains, where I have to really work hard to read some of those names. I think it's a matter of similar frequencies in line density. By that, I mean that a label like "The Elderwood" isn't as difficult to read because the linework surrounding it is very high-frequency. If you look at "Briggdorum Mountains," though, it's difficult to make out because the frequency of the surrounding mountains lines is very similar to that of the text. The letters of both appear to be the same size, and I assume that the padding around them is identical. So what makes one legible and the other not must be the patterns across which they are placed.

Along those same lines, there is a contrast issue with some of the text on the forests. Take a look at the labels "Jui-Rae" and "Jui-Sae." One is easier to read than the other, merely because the density of the Jui-Sae forest itself is greater. In that case, it's not a huge deal, but it might be something to keep in mind for the future.

Well, I need to get back to work now, but it looks good! If I get the chance later on, I'll try to take a look at the full-resolution version.