According to the devs, they specifically designed the game so that you could play through without killing anyone if you wanted to.
Yes I know...but can you really do that?
Judging by how fast unconcious people got up in Fallout 3 a fight with several opponents could be never ending.
I was going to try the beanbags but unfortunately during a particuarily hectic battle with cazadores I accidently loaded and fired them all after I ran out of regular ammo...doh.
Good to know they can be crafted though....something else I don't do on my first character