Good summary Scrubcedar.
I'd add, regarding shotguns vs. lighter weapons:
1) A shotgun is (IMHO) more intimidating than a rifle because you CAN see down the barrel when its a couple inches from your face (first hand experience
2) A shotgun's physical size and weight also make it a non-lethal albeit formidable club type weapon - be it a whop-up-side-the-head or as a quick jab extender