Thanks again for the (painful) memories, Lou! The movie, 1, did not go into nearly that depth about Jochen's crash, but in it, Eddie Dennis says that Jochen asked that the wings be taken off. Memories can certainly fade after forty years and given Chunky's penchant for going for the bleeding edge, it sounds in character for him. Miles said in the movie that without the wings, the car was undrivable to him and it was the only time he was really scared in a race car.
A couple of other points: In 1, John Barnard states that the first job of a car designer is to make the car fast (left unsaid was that safety was secondary). Also, I'm reminded how Regazzoni crashed heavily at Long Beach, ending his F1 career, when his titanium brake pedal broke. One of my engineering professors was appalled they would allow titanium to be used in a welded critical piece like that. But for those caught up in it, it was all about how to make the car fast and safety was secondary. It wasn't just Barnard, or Chunky, or Rindt. Ironically, Jochen may have been the first driver to refuse race a car (Lotus) because he didn't consider it to be safe. Whoever made the decision to take the wings off - it was done when Jochen and Lotus had a nearly unassailable lead in the championship.
As for not wearing the crotch belts - I wouldn't be surprised if that had been the final determining factor. Racing harnesses were not commonly used then. I believe it was Mansell in the movie who said that the idea was to get thrown clear in the case of an accident. I'm certainly not in a position to disagree, but I did read that when Gurney was driving his magnesium tub Eagle, he was acutely aware that if he got a flat, his car would likely catch fire and it would be impossible to put it out. He said he chose not to wear belts so he could get out quickly if he had to, but that may be a distinction without a difference.
Watching 1, I am impressed that so many fatalities could have been avoided by using simple safety equipment and employing reasonable track marshalling even without the fancy carbon fiber tubs that protect drivers so well now.