First its just a little unrealistic how they walk through no-collide walls.

These two models textures are overlapping causing that gitter effect between textures.

I see you tried to clip this rock here, might wanna move it back just a little as I can get on the back of it.

For this it would be good to use the clipper tool to cut a square out under the middle of it, that way the brush doesn't stick through the bottom

Also as for the black ops weapons they are very nice and add another gameplay element into the map which is good, but I would suggest using those weapons default sprint animation as the one that is currently being used is changing the look of scale on the gun. Treyarch usually just zooms in or out how close the gun is to the face to make it look bigger or smaller.