Add McDonald v. Chicago, 561 U.S. 742 (2010) where the Supremes incorporated the 2nd Amendment against the states, forcing Chicago and its suburbs to allow gun ownership, and the case law WRT to states and the RKBA is clear.
It’s very doubtful the number of households that own guns has decreased since 1960, when the latest round of gun control was just starting to get strong (I came of political age in the late '60s, so I directly remember this). Responses to anonymous telephone callers asking if you own a gun roughly tracks how successful gun controllers are at the time.
When I did a back of the envelope calculation about the claims by the usual suspects that existing gun owners were buying all the new guns as of late, it would have us owning about $100K worth of them on average.
The increase in ownership for self-protection no doubt tracks the nationwide sweep of “shall issue” concealed carry laws in the states starting with Florida in 1986, which went from less than a handful to 42 now, covering most of the population. If you don’t live in Illinois, this state level political effort is is the single biggest change since 1968, and the biggest change of the facts on the ground since the early 20th Century.
Without looking at [13], obviously you can turn around the implied causation to “For every 0.9% of firearm homicides, there is a 1% increase of people in a community owning guns.” Although simply being allowed to legally carry them outside your home drastically increased their utility. Handgun sales in total and of their type track this.
In the US, gun buybacks are an opportunity for savvy gun owners to sell junk for more than it’s worth, and to work the line looking for valuable guns about to be turned in for a nominal payment, and buy them for much more like what they’re worth.
You no longer believe strongly that "Gun ranges have a net positive impact on gun safety because inexperienced people are taught by people who know how to handle weapons." and you're right from my anecdotal study. Going further, I'm beyond amazed at how well poorly or not at all trained and experienced people responsibly use firearms in self-defense. Chalk it up to centuries of improving ergonomic design in guns, reaching perfection for handguns a century ago, a healthy gun culture, perhaps even Hollywood (although the gun handling on screen is generally awful), and informal training, which I've done my share of.
"Has concealed carry successfully stopped shootings?" Well, it's certainly stopped the wrong people from getting shot, now even in Chicago after the Federal courts forced shall issue concealed carry on Illinois.
"Lock up your safety" laws like California's has definitely killed people. We in the gun community of course encourage locking up most of your guns most of the time, but I doubt you'll get good statistical evidence on anything about this.
America has way too much "empty" space to make restrictions on using guns only at formal firing ranges.
While I can't prove it to you (should you even believe my personal pledge?), such restrictions, or an Australian style gun confiscation, would turn our current cold civil war into a hot one, and a lot of people would die on both sides. The most recent evidence for this is the small fractions of people in the Bluest of Blue states of Connecticut and New York who registered their evil "assault weapons" (a purely political term) after Sandy Hook inspired legislation. If you can't succeed there....
ADDED: you have to be very careful interpreting the "research" some people and outfits do. Best example is the infamous Kellerman study in the once prestigious NEJM which, even before you get into all the lower level problems, scores a "success" for a gun owner only as killing a home invader. Needless to say, out of the 2.5 or so million gun self-defense incidents per year, only a small fraction even involve a gun being fired, let alone hitting, let alone killing an assailant.
(As a rough metric some time ago but after trauma centers were established, I've read that one handgun round into someone's torso has a 1/4th chance of killing them. Mostly anecdotally, as many as 1/2 of all assailants stop attacking after being hit once, even if the hit is not immediately disabling).
While I didn't look at all your sources, or closely at the ones I glanced at, I didn't see any notorious howlers like Kellerman's.
ADDED: for someone apparently completely uneducated on the subject, you did a fantastic job for a few hours of effort.