I need to clear one thing up. This information about a state trooper coming to a range and deeming it safe if there is a question/concern - I'm 99% sure I heard this in my CHL "instructor" class, meaning from Sargent Baumsch of the TX DPS, the guy who taught my week-long instructor class when I became an instructor. He explicitly did say we no longer have to certify a range, but I can't recall if he is the one who said the other bit about a peace officer or someone like that coming to inspect a range, only after a concern or question was raised about the range. As to how they would deem it safe, I guess it is their judgment. I've never had anyone do this at ranges I know of, but I know LEOs who frequent those ranges too so I'm sure if they feel it is safe, it is safe and there is no arguing with them..
I know some nearby ranges like this guy in Liberty Hill, he's had LEOs come out on several occasions after complaints and they always find it to be safe, so there's nothing they can do (the county doesn't regulate it otherwise [yet]).
Well, according to the laws that I just made up - which are as good as anything else that's been posted in this thread so far:
You are limited to 25 meters for shooting rubber bands,
15 meters for spitwads
100 meters for slingshots
1 football field for dirty looks
25 miles for rail guns produced before 1920
1000 miles for rail guns produced by the aliens we're keeping captive at area 51
...and no one is allowed to fart within 50 meters of yours truly!