1. The Us were nervous because he was
2. I would view the U.S poorly. To let someone get assassinated is devastating. ( I was kinda confused on that one. Sorry!)
3. I think it was wrong that the U.S did nothing to stop it. I think this because just because he was leaning toward the Soviet Union for help doesn't mean you have to kill the person.
4. This is an opinion question.
I say kind off. There are other important people who got assassinated too.
Hope this helped!! sorry if not!