NC, I think anyone would be upset to hear their children were in danger. No 2x4s from me. I do think this one should be at the top of the list for the parenting coordinator!
Re: your S8. I used to overhear comments about my D10 as well. She would constantly be in motion and liked to jump around (like Tigger) for long periods. Around 9 years old though it just seemed she grew out of that quite a bit, and then I started overhearing everyone say how great and well-behaved she was. This past summer when she was in the play, one of the teenagers was telling the other kids they need to act more like my D10! I think boys take a little while longer to mature than girls too, but I think you will find their behavior gets gradually better and better, or at least that's been the case with my 2.
