Re: If the author wanted a "killing is always wrong" shpiel, he picked the wrong villains.
I'm not sure paralyzing Joker from the neck down would stop him. I remember a story I know was posted in the old com where Joker gets an inmate in the cell next to him to kidnap a child. I doubt that was the only time he was able to cause harm without personally or physically doing something.
Now if there was some way to put him into a permanent coma it would work.