I have no problem killing slugs. But that is about as far as I go. My two labs chase away the woodchucks, rabbits etc. my son shot a deer in the woods next to us. He and his family ate it, but I didn't have any taste for it.
When I came home from Vietnam, I couldn't have a gun in the house. I have no problem with those who do, and I defend individual right to own them. Just not for me.
My dad was a Vietnam vet and when I was a teen I asked him why he didn't hunt any more like he did when he was younger . . . he said the same thing as you . . . he had enough shooting and killing . . . didn't have a problem with other folks doing so, but it wasn't for him.