Counter-point : maybe the shooter chose THAT grassy knoll because that general area was less crowded which makes it easier to stay hidden and undiscovered. Basically your #4. It helps support the "not a conspiracy" argument just as much or little as it helps the "conspiracy" argument.
so are you saying its possible to believe there was a shooter in the grassy knoll but that it wasn't a conspiracy? I thought that by definition, if you believe there was another shooter, you believe there was some sort of conspiracy.