First of all, great first post! This is very interesting and in many, many respects it's admirable!
Now, for suggestions I would first of all say it is an odd amalgam of three different styles: symbolic (the mountains & hills), realistic (the forests & rivers), and painterly (the deserts & coastal waters). These three can coexist, of course, on the same map, but I think on your map the gulf between them is too great and thus jarring to the eye. I suggest you find a middle ground: make the mountains a litle more realistic by adding shadows/cliffs/snow/line variations; and add a but more realism to the painterly elements as well such as grain or splotches.
(Plus, the Lost Lands is a giant eyesore--perhaps because it's so bright? I'd try it very dark brown or black, etc.)
I really like how dark the sea is in comparison to the land, although I wonder if the land is just a tad too bright. This would, perhaps, be dependent upon the tone of the story you are writing: is this a hopeful tale of high adventure, or a tale of dark times. Make the map fit that, I say.
I think this is the best starting place for the next stages, IMO. I look forward to seeing more! Great post!