You could connect the river at Izwar with that at Ghami, leaving the fertile area alone - one doesn't have to have lush farmland the whole length of a river. Then up north of Gharji you could continue the river around the eastern end of that range, flowing down to the sea through desert and arid lands. That's plausible - look at the lower Nile !

My family took a hike a few weeks ago to a nearby cave where a mountainside creek disappears. It's pretty minor creek, but that can happen !

I like the map - bar a couple of jarring things like rivers that go nowhere :-) it hangs together very well.