The only issue I can see with the rivers (Aside from questionable non-draining lakes that we can just say are salt basins) is the river on the bottom right, the one that flows out the corner of Tharais. The mountain range continues down, but the river seems to flow back into its path. I would have expected the river to stay more north/west of that location and drain sooner. As it is now it looks like it randomly goes to what should be an up hill region.