The issue with the covid19 vaccine is that you can no more prove that a death is due to the vaccine than you can prove that it saved you or reduced the severity of the illness.
Yes, and no since most people are genetically different. And when it come to the shot, genetically similar people (AKA family) stick together. They either get it, or they don't. But . . . . my wife and her niece are very similar genetically. My wife had Omicron last year, as did her niece. My wife was "sick" for a week and had relatively mild symptoms. Her niece was "sick" for a month+ and was down hard. My wife is up to date on her shots. The niece has never had one. This was a true apples to apples comparison.
This year, I've had whatever variant it is. As last year, my symptoms were mild, and gone in a week. My wife still has not. But we couldn't be more genetically different. Everybody that I know, that has had the shot, has reported similar experiences: mild symptoms, and gone in a week. Those that are not up to date on their shot(s) have been sicker, longer. Not scientific research, but it is real world.