Linoge has a lengthy transcript of the recent “wild west shootout” from a few days ago (labeled that because the good guy took care of the bad guy with a single-action .45 Colt revolver).
It contains a great many details about the event and the lessons one can learn from it.
Some things I picked up:
- Fight. You’re not dead until you say you’re dead, and the fight isn’t over until you give up. Fight. Fight. Fight like hell.
- Get yourself good hardware, solid, reliable. Once you have yourself a good solid gun, get lots of training, and practice.
- The training shouldn’t be just marksmanship style training, tho certainly that is necessary. A lot of the training should be things that help you with situational awareness and other tactics, things to help you avoid the fight if possible or if the fight must happen, to give you every advantage you can get.
- I’ve said it before, I’ll say it again. All pistol rounds suck. Bad guy was shot multiple times, apparently a few were critical hits, but bad guy kept on fighting. First thing I said remains true: fight, because you’re not dead until you say you’re dead. Works for both the good guys and the bad guys. Make sure you work it to your advantage.
- Scumbags are scumbags. They don’t care about you or anything other than themselves. If they’re going to go to jail anyways, what’s killing a few more people along the way? Hell, to them they probably view it as a good thing towards increasing their “street cred” to be able to rattle off a big number of how many people they’ve killed. Don’t think you can beg your way out or expect any sort of mercy from them.
Go give it a read. Learn what you can from it.
Stuff From Hsoi 
All pistol rounds do indeed suck (especially considering that it took three rounds of .45 Colt to bring this dirtbag down), but carrying a rifle or shotgun is a bit difficult (and generally illegal to boot).
Your first point is definitely your most important, though. No matter the tool, no matter the training, without the will to do something with all of that, it is meaningless. However, the tools and trainings are necessary to equalize the playing field once you are engaged in the fight… or, better yet, skew the field in your favor.
Legality of carrying a long gun depends upon the jurisdiction. For instance, I could bring a long gun into an alcohol-serving restaurant in Texas… someone would likely get their panties in a wad if I did. And it’s rather cumbersome and inconvenient, thus why we carry handguns.
As the cliché goes: it’s not the size of the man in the fight but the size of the fight in the man. But having better tools helps. 🙂