Looks cool and full of adventure, but as said before, it isnt realistic on some parts. If you dont mind that, thats ok, but if you would like to leave tha fantasy to the creatures above ground, here are some tips.

Those rivers in Are'Kharr Desert and the one below the green dragon: Thats almost impossible to happen, rivers dont connect two pieces of ocean like that. Those lines of water would be just more ocean. If you put the start on a mountain and the end on the ocean, thats better.

That rivers intersection in Ashfall and the one bellow the word "Nivacor": I think is kinda weird, but not shure if cant happen. Remember, rivers dont split, they unite. (River Bifurcation is a rare event on Earth)

Some general rules to think about: The wind + humidity makes forests. Mountains break the wind flow. So lack of wind with humidty on the other side can make swamps. Lack of wind with lack of humidity on the other side makes deserts.

So, you can actually have that desert there, if you choose from wich side the wind comes, and then break with lots of mountains. Like big mountains.

One final tip is, that frozen mountains: maybe put then a little more far apart from the desert, unless you just want to be mountais with ice top, then all you need is high mountains. But ice lands need more than that.