Okay layout for the first, simple, a bit ash like.
Always when you don't have roof in your map, think about it's effect on play. I can imagine a lot of m79 boosting there cos there's nothing stopping you flying in air, there's also "normal" jets, which is damn a lot for this kind of map.
1140 polygons are too much. Use always minimum number of polygons that way you can prevent fps issues and polybugs. Also overlap your polygons to prevent, again, polybugs.
Looks good
. I like the themeing. Welcome to mapping scene!