I don't see much problem with restricting right to own/used based on conviction for crimes of violence or mental incapacity (if someone has the mental capacity of my Labrador retriever(overwhemingly friendly as he is)--they probably should not have a gun) or someone that is paranoid/schizophrenic.
I do know that when kids using 22s for hunting/target once their age hit double digits--criminal misuse of firearms was much less.
For the first part, most of them probably shouldn't even be out on the streets - when I was in med school a little more than half century ago, they weren't. We're more enlightened now.
For the second part, I dunno about "double digits" but here I am in 1934 wIth the .22 single shot rifle I got for my 6th birthday in 1932 and my "trophy rabbits".
By 1934, I was officially registered as a "gun collector" because a friend of my dad's gave me this stunner (for me at that age anyway) .410 pistol H&R Handy Gun.
Unfortunately, within a year, the BAFT (tax collectors then) declared it to be as dangerous as the Thompson Submachine Gun and , on the NFA registration form in answer to the question as to why I justified owning "such a weapon", I claimed I was a "gun collector". I was almost 8 years old.
My "collection" consisted of the .22 rifle, .410 pistol, a double barrel side by side .410 shotgun, and a Winchester 94 in .32 Winchester Special.
As can be seen, I have changed a little but, my interest in rifles has continued at a somewhat higher level. So far, I've not yet had any AD/ND or firearms violations - but it's not over yet.