It's the same for the pump. Both types have a safety, etc.
For a gun owner like the OP, someone who won't even look at the gun after he buys it and fires it, a revolver is the only choice.
As far as size, even a shotgun w/18 inch barrel (one of my bedside guns is a Remington 870 express HD) is still a big gun. Fine for someone who takes the time to get and stay proficient, but that's not going to be the OP. He'll buy it, shoot it, and store it.
I wouldn't be quite so absolute about the handgun vs shotgun. Hitting the target is everything. If someone isn't going to put time into practice as you said, any shotgun is better than a handgun IMHO.
I learned shooting a firearm at 10 years old with a 12 ga. Then I moved to rifles. Both were easy to learn and use. To this day I can hip shoot better with a long gun than I can in my best modified Weaver stance with a handgun. Ok, I've got 30 years more experience with long guns. But still...