Being a gun enthusiast, I will say this....there is no way ONE man could make those shots from that range...especially with that peace of shit rifle Carcano that they found. Also, no matter what anyone says...bullets DO NOT make 90 degree turns...that is impossible. Also, too many people say they heard shots come from the grassy knoll. I'm sure Oswald had something to do with it...but he didn't act alone.
Although I agree with most of your post I would bet money 9 out of 10 qualified shooters could pull the shots off. Its an incredibly short shot and if you allow for the first shot to already be chambered the only tough part is working the bolt action fast enough. Picking the sight picture up would not be hard at all as you do not need the scope and would only use the iron sights. Plus recoil is not a problem as the window frame and boxes make for a great shooting position. I do not believe Oswald was a part of the kill team in the plaza. Been on the sixth floor, looked out the next window over and its really a not a tough shot at all. The knoll would be much much easier though.