LOL. i know what you mean by the ol' D&D maps, but I have also been staring at atlases for longer than playing D&D (and that for about the same as you) and I was referring to the actual coasts. They do seem to have a lot of sweeping arcs to them. In satellite view, look at the Bay of California at your scale, and while not necessarily jagged, the coast is not quite so smooth either. Those arcs have little bumps and indents and other non-smoothness to them, with little bays and such.

Like I said before, I like the layout you have, just think it could use a little "irregularity" if you get what i am saying.

BUT then again, this is still in the early stages and it really depend on the style that you are going for. So seeing as how I like the layout, I should really let you develop the map a bit shouldn't I......I will be quiet and sit on my hand now...