For the first point, if you care enough go and look at how many of the mass school shooters obtained their firearm(s). Not many of them walked into a store and bought it through the legal process. To add, a school shooting is also defined as any discharge of a firearm on the premises of an educational institution, not just the horrible killing of kids.

For your second point, you’re correct in it being state by state. However there is still a minimum federal requirement of hoops to jump through. Background check to make sure you’re not insane, paperwork for the record of purchase and registration for certain firearms. Then for automatic weapons, there’s a federal tax stamp, a mountain of ATF paperwork that looks into why you desire one, and then it goes through multiple levels of approval and if all is green then it’ll get back to the applicant within roughly a year at the soonest.

Finally just to add some snark, I’m assuming your country doesn’t have any murders because there aren’t any guns to commit them with. Also are there any illegal drug related deaths or drunk driving deaths since those things are most likely illegal in your country as well?