hard to tell if stretching is just your SS's since there's no bsp. but...
1 & 2. add a texture to that black wall.
5. wth is that thing above the flag? either get rid of it, or fix the texture so we know what it is.
6. change the texture of the stairs themselves to a stairs texture. that doesn't look like stairs. Why is grass popping out of the stairs.
7. re-align all of the crate textures, and the hump next to the crates.
Overall, all the areas seem rather empty, add some earth mass (divots, hills, rounded ceiling in cave) so it looks less square.
