500 yards...1000 yards...still not a mile . Do you know how many yards are in a mile even?
Your #1 depends on a lot of things. You can argue that there are some cartriges that can travel over a mile (which I've only seen you provide "stats" for the 45-70 so far), but that doesn't mean they're deadly at that range. I don't know where rifles even came into this...the cop was using a handgun, which is not going to go very far at all in comparison to rifles. I don't even know why you're bringing in examples of people that are purposely trying to hit things at great distances, when the conversation was about firing randomly into the air. Its simple: A falling bullet traveling at 9.8 m/s2 or a little greater will not kill you, unless you're an infant or over 80, or you have osteaoperosis.
Though you've got a lot more experience than me with guns, you don't have anywhere near the experience I do with physics. 9.8m/s2 is not enough, end of story.