Here's my thoughts. (I'm not going to read this whole thread)
We live on a farm/ranch. In order for our children to be safe on our property they were taught young how to behave around horses, cattle, equipment. You can not take an 18 yr old kid and stick him on a tractor. In order to be able to safely drive that tractor that kid has to ride with dad in the combine when he's four, watch the guys change around the implements when he's five, watch mom saddle a horse and ride with her when he's little. They learn how to shift gears, read the dials, tell when a steer is going to charge you, know when a horse is getting cinchy. All of this is a basis for as safe as you can be on the farm.
Guns too. Ours learned gun safety young. Not as young as that, but the poster is exaggerating to make a point. You don't hand an eighteen yr old a gun. You don't hand a child a gun. But you can begin to teach a child gun safety at a young age.
And yeah. If someone wants to hurt you a restraining order isn't worth shit.