1.Rittenhouse said it was 'his job' to defend the buildings and administer aid to people there. It was not 'his job:' nobody hired him to do it. He was engaging in illegal vigilantism and was illegally breaking the curfew to do it.
In what world does the fact that he was volunteering rather than being paid make guarding a shop and helping out as a medic vigilantism?
2.This is something I haven't seen mentioned anywhere else, and it seems such an obvious point to me: Of all of the vigilantes, rioters and protesters there, he was the only one who killed another person. Irrespective of whether he acted in self defense or not, nobody else there, in that intense situation, had a problem where they had to kill another person.
The too-obvious answer is that he was the only one who was attacked like that.
It's worth asking why he got into a situation where he was attacked, and the answer to that seems to be that he was the only one who went to act as a medic and help put out fires, which isolated him from his friend back at the shop when the police moved.
Irrespective of anything else, Rittenhouse is clearly a mentally troubled young person with some kind of need to be a hero, or who sees himself as some kind of hero, who was completely in over his head, untrained and ill prepared for what he chose to get himself involved in, and, as a result, two people are unnecessarily dead.
And what's your psychoanalysis of his attackers? Surely more in over their heads, untrained and ill prepared for what they chose to get involved in, than Rittenhouse?