Looking good. I like the mountains a lot.

The colours are looking very dark on my screen. Might be worth lightening them up a bit. For the sea, I've found that an overall radial gradient focused in the middle can really help - it pulls the eye towards the center of the map. It can be very subtle.

I see what you mean about the hills - they're quite sharp. Are you going to drop the mountains and hills back from pure black? You can experiment with this by creating one layer will all th linework on it (a copy of all your other layers of course), clicking lock transparency and then painting over your lines directly with a colour - dark brown for your hills, and perhaps a darker grey for the mountains? That might ease them into the map a little. Or it might look rubbish, but it's an experiment that won't break anything.