there are several rounds made in low recoil loads. If you are worried about recoil and overpenetration, but still want to use larger pellets, try those out in 00 buck
I personally go with your 2-3/4" Remington Express 00 buckshot. I also have some #1 as well, which I like because there being more pellets. I live in a neighborhood where there is enough space that everyone has a nice yard, so the overpenetration thing isn't an issue for me.
also, if you are using a gun (especially a shotgun), you are using deadly force. A firearm is a deadly weapon. The court will not likely see it any different. With that in mind, if you have to shoot someone, you might as well stay with that intended purpose and do it right in order to make sure that they don't come back with their own deadly force or their lawyer.