Buttstock, I found your post to be a very good one when it came to choosing a handgun for self defense. One should always consider the effects of stress and the training/experience level of the user. I bought a S&W Kit Gun, in .22 LR as a self defense gun for my first wife because that's was her level of training and experience.
I would suggest, however, that you test a shotgun at across the room distances. At those ranges, the spread of the shot isn't useful. Powerful and deadly, yes. But it works like a rifle at that range. You need to be 15-20 yds from your target before the pattern spreads much. E