I think a problem could be that it's the same type of coast everywhere.
The type at your map is the one with many small bays and little, not too sharp pieces of land sticking out into the ocean.

I just found a satellite photo of Europe at File:Europe satellite orthographic.jpg - Wikimedia Commons

There you could find the zigzag-type at Greece and elsewhere at the Mediterranean Sea, but at the Atlantic coasts you also find the type of long, calm lines.

I'd suppose you could create some changes between those styles on your map which could help to make it look more naturally.

And, as Diamond said, the zigzag-type is too regular. Though I'm curious how the work goes on... although I don't see, why the dwarves need to speak a German-like language. (we are no vikings, at best some German tribes with a piece of romanisation)