Yeah, I think you're right about the landmasses being too "craggy". That there is that many scattered islands around every continent seems unrealistic. I'm guessing you've been using cloud renders to generate land? I think you need to manually edit the results, if you want something more believable.
And the white "drop shadow" on the land is also noticeable. Is that a layer style, or could you solve the problem by moving the water layer a few pixels up and to the left? Then you might have highlight around all the land.