Even if you could prove to me that guns were used in even half of those cases I would still say your argument has no merit. Having a gun makes no difference in those situations. If you're so pissed off that you're going to kill someone, you're going to find a way to do it. People have been beating, stabbing, bludgeoning, drowning, choking and otherwise finding ways of killing people they dislike since the dawn of man. It's foolish and naive to believe that guns have anything to do with it.
In fact, I'd say gun ownership does more to prevent crime than it does to encourage it. If I'm a big guy and I figure that I could throttle you pretty easily, but I know that you carry a gun, that may dissuade me from assaulting you. I'm not going to say with 100% certainty that it will - that would be hyperbole. I will, however, assert that it would change a lot of people's minds.