Well the rivers are of course absolutely not feasible, especially the ones to the south. Most of them also don't seem to extend far enough inland for their width, but then again these could be creeks, fjords or something similar.

The rivers also seem to be bordered in a reddish color, but I am sure this is my colorblindness striking again and it's actually green?

As for suggestions for improvements - it's a bit barren right now. Give it forests and/or settlements. Add a compass rose, a scale, and maybe labels for important features.