Those things bugged me too. Again, I'm expecting them to tell more of the back story to this thing to tell us this stuff about the hundreds of people in one location stuff. And it seems like they can just move about without much concern during the day, why is that?
But the "fighter" vs. "civilian" thing was a big annoyance. These 200 civilians, they showed a bunch of men. I'm sorry, but if my life and civilization as I know it are being threatened by an invasion, I'm not going to be sitting around watching the "fighters" (which include what look to be two teenage girls) while I'm fetching water from a river.