Beautiful map! Have some REP. I see no river problems, so well done there. My only question lies on those two areas, the southwest corner of the map, and that area north of Marabzi, and east of Mardosayo and Ushenshe - are those desert area or something? I notice the borders don't close in there, but they seem to match the color of the sea. I'm guessing a great chain of mountains encircle Mardosayo and Usheshe because all the rivers there flow to the west coast into one great river.
Those empty areas confuse me. Other than that, great map!