Repman, I'm sorry, but the data you provided has flaws. I did some very quick internet checks and found errors. In fact, Australian gun control has worked. Though the numbers of homicides in Australia was reduced, because there were so few anyway, it is basically statistically irrelevant, just as posting there was an increase is statistically irrelevant. What is relevant is that the number of suicides dropped 75%! Is preventing suicide enough of a reason to try to come to grips with our obsession with guns? Myself, I believe that a lot of the mass killings we have are suicides, anyway. They just want to take a bunch of people with them. Guns allow that. Most don't take the time to put together bombs. I do agree with you that hatred, mental illness, dysfunctional individuals are the ones doing the killing, but guns are the great enabler. Very few seem to take the bomb route. Why not talk about a way to reduce accessibility to the enabler? If, as you say, they would just find another way, why haven't the suicide rates in Australia gone back up to where they were before the gun restrictions? Guns make it too easy.
As to your "fact" of "the myth of the 90%", the U.S. Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF) has repeatedly said, "these guns are most commonly traced from organized crime scenes south of the border back to a U.S. point of origin, even if some were legally imported to the United States before being sold by a weapons dealer and then smuggled into Mexico." Your source comes from a known "FOX news" personality. A well known right wing propaganda organization who has repeatedly shown that they don't care about the truth, but only their view. I think I'd take the word of the ATF over the extremely biased right wing reporting of FOX, any day.
I should also point out, that those are the only two of your "facts" that I have even researched at all and only briefly, at that. I suspect I'd find the other "facts" just as false.