The most effective way to achieve many of these goals is to teach gun safety to everyone, including age-appropriate training for children. That way when a gun owner fails to do the right thing, those around him are less likely to hurt themselves, and more likely to recognize the unsafe behavior and correct it.
I think we don't need to involve children in weapon issue. It's not enough to just teach gun safety to people, the main point is why people need the gun in their home, and also you must need a license to using a gun.
In my experience ignorance is more dangerous than knowledge. I think it makes sense to teach kids what to do if they find a gun. Just like they should learn to swim before falling into a lake. In the U.S. there are many free/cheap programs to teach youth gun safety. The apple seed project for example, or the hunter safety programs sponsored by most states.
Even though she is a fairly good shot, my wife has little interest in guns. But I insist on her visiting the range once and a while to keep up her basic safe handling skills. If there is going to be a loaded gun in the house then every family member should be able to:
1. Children or those who know nothing about guns should know to get an adult if they find a gun and know to stay near and keep any other children from touching it. Your guns should never be unattended or kept loaded with young children around.
2. Older children who have shot a gun may be trained to cover the gun with a bucket or something and guard it from other kids. But again, your guns should be locked up at all times when children are present.
3. Adults who are familiar with basic gun safety should be able to disarm a firearm and block the breach. If they can do this then you could keep a loaded gun with that adult present. But it should not be a surprise.
P.S. - I think it is true that in every state one can keep a loaded long gun in their home or shoot at a range with no licenses of any kind. It is only carrying the gun hidden on yourself that requires a CC license.
https://appleseedinfo.org/search-states-map.php