To answer an earlier question: your rivers look alright. None go through mountains or anything :p When in doubt it never hurts to check nature's examples Keep in mind by the time they get to a mountain slope they are significantly reduced in size. Overall I like the direction your map has and that you have considered climate and rain shielding! Consider widening your mountains. If it is in photoshop take the layer and use the transform tool to widen them (ctrl t). That said mountains can definitely have very sheer and steep slopes like the matterhorn for example.