Man a whole different arc in season 2/3. Changes to season 5B.
There was supposed to be a cartel boss (that later got changed into Gus) that would tell people to pick a random number between 1-33. Then he'd have them held down and knock out that vertebrae (because there's 33 vertebrae in your spine) with a chisel and a hammer. So you were essentially gambling with being crippled for life.
Anyway, that guy was supposed to kill Jesse. Walt was gonna kidnap dude and have him tied up in an abandoned house in the middle of nowhere. Walt would go out and randomly torture dude, as revenge for killing Jesse.
Walt had a gun set up so the guy could choose to commit suicide to end his own suffering. But the guy was a beast so he just took the torture.
One day Walt's son follows Walt out to that house, and finds the guy. When he tries to help him (since he has no idea who he is), the guy triggers the gun and kills them both.
Also, in season 5, Skyler was supposed to leave ABQ, with the disappearer guy. She was gonna slit her wrists in the bathroom, in that cabin in New Hampshire while Walt is trying to talk to her right outside the door.
Also, during "El Camino", Jesse was supposed to have insomnia the whole movie. Then at the end, when he's about to disappear, he sees a woman being robbed and tries to help her. Ends up getting caught and going to jail. In jail for life, he can finally sleep.
Fred.