Good job. I'm only 22, and a regular weekend fixture at the range, so I see this stuff sometimes as well, and I also know how it is to not be taken seriously because of your age. at the range I currently go to, it is largely unattended, self-policed, and off the beaten path, so I rarely have problems there. Most of them deal with plain ignorance (one of my friends was fiddling with a gun while someone was downrange, so I explained that range safety/etiquette dictates you don't handle anything while someone is downrange.) All the idiots seem to go to the other range, hence why i don't go there anymore.
I also agree with trying to cut them some slack. Everyone makes mistakes, and everyone needed to be taught these skills and rules at some point. Very rarely, even I will sweep someone. I get really embarrassed when I realize it.
Over all, good job. happy shooting.