I think the only person you can kill that just makes you look like an ass is an unarmed character. Once I decided to see what would happen if I went around to random places in big cites and sat down. I dropped all my gear and just went around Cherno and Elektro. The first guy I met stopped to chat and even bandaged me. Every other person shot the random guy sitting at the bus stop, the middle of the street, and church. Even when he offered them drinks. And on your sniper friend, I agree that it is different, just not in the way he thinks. If the guy is running around either unarmed or with a hatchet/crowbar, unless you're guarding a stash or a friend, there is no point in wasting the bullet until he has a gun and actually poses a threat.