We have four children, and I had guns all over the house long before I even met my wife. At the risk of sounding a bit terse, the real issue is one of obedience, not curiosity. We never baby-proofed our house, we just took time to explain to them from day one that some things are "No-No's" and never cut them any slack. My house is also full of knives, swords, razors, kama, axes, - we're a virtual museum of human destruction, yet we've never had an incident because they were taught. If any had /has a question about any firearms (or other destructive object), we would/will break it down, spread it out on the table, show how the parts work, re-assemble it, and do a "dry-fire" routine together (or take the object in the back yard, and learn to swing/hack/throw/whatever), thus leaving no reason or excuse for secret explorations. They figured out real fast that it's more fun to be taught properly than to try to "guess" at something. For one, it took 4-5 times per gun; another one was totally sated and bored half-way through the first run. They all still know that they need only ask and we'll do it again, no problem. (FWIW, they actually index their trigger fingers on their water pistols while chasing each other in the yard. They really do learn!)
Back to the "obedience" thing: If they have no excuse to disobey, they are less likely to. They are small, but still sentient.
Another "Plus" is that they have always been welcome (as in "invited," not just "accepted") at other's houses because they didn't mess with things that they knew they shouldn't.
Admittedly, the fact that they have all been home-schooled has a lot to do with it, too - any outside influence that tried to usurp our authority as parents was discussed, then dismissed - permanently, if need be.
I hope this helps; at least, something to think about. I've always believed that children are marvelous critters that will live up to - or, down to - the parent's expectations. I expect mine to be civilized and polite, and they know it.
Enjoy your kids every moment. If you don't, they'll know. :yup: Parenting has been the greatest privilege (and adventure!) of my life.
Stay safe,
Chuck Brick.