Your rule citation is good. Also, look at the rule citation about act designed to make pitcher balk. 2.0 defn of interference. And, finally, since it is LL, catcher safety. Cut if off.
Umpires have discretion over unsportsmanlike conduct.
Let both teams know you consider it unsporting and that the next offender who waves the bat wildly will be ejected. He also mentioned that as a pitcher, he might get so distracted that he could accidently hit a batter. I thought I saw a twinkle in his eye when he said it, so I immediately reminded him that throwing at a batter, no matter how obnoxious his behavior, is absolutely forbidden in baseball at any level and in this house. I would never work a softball game. Small diamond ball should include teaching, we can teach by following Moose's process and everyone will come out a head.