It looks as if you might need to tighten some areas, thats what everyone keeps saying about my map.
However, I havn't played it so I'm just going on the screenshots here.
There doesn't seem to be many boxes/barrels lying over the place. In most maps these are good for retreating players to hide behind, or spies to decloak
In screenshot 3, it feels like there should be some small stairs onto that point. It looks too high to step up and the only easy way I can see onto that point is by going through the building. You might be able to jump onto it, but there should probably be steps or a ramp or something.
Screenshot 4 feels a bit open, but open doesn't always make a map bad. Dustbowl is very open around its first points of the stages.
Screenshot 5 & 6, I think it might be better if you added some wooden barriers where that rock is. There's a fair sniper sightline there, and one sniper could cover those tunnels easily. I'm not sure where the attacks/defenders are coming from though, and it might not be a problem.
Screenshot 9 (Point in the corner), I feel there should be some sort of cover either on the point or in the area next to it. Due to it being a corner, splash damage of rockets and bouncing pipes would dominate the point to much without some sort of cover for sentries or players.
Also, now I know its alpha, but the wooden logs coming from the building in the first screenshot look a bit strage clipping through the roof, but it is alpha...
Thats my feedback based on the screenshots, but all of it could be wrong, I havn't played it yet. When I do, I'll provide some more detailed feedback.