Heres my feedback:
1.
When you get in this rock its not solid on the inside,therefore you can shoot through.
2.
Inside this rock its solid(you cant shoot through),but a cheap way to advantage over enemy.
3.
When you go prone and crawl in the rock this is what happens:
4.
When you walk over to this cave wall,this happens:
The good thing is that you cant shoot through(it doesnt allow you to),but still a cheap way of spotting enemies.
5.
When you walk over to this rock,this happens:
It might look as if im on the outside,but im actually inside this rock.Its big enough to hide you.
6.
When you walk over this rock,this is what happens:
You can hide in there and can shoot through.
7.
I dont know if its intentional,but you can walk over this.Here's a look from the inside:
But on the other end of this hut you cant walk in this secret room: