In my estimation, Arlen Specter's single bullet theory, coupled with the rush to repair the damaged limousine and quickly exit Kennedy's body, says there was a conspiracy at the highest level...
What other factors tell the story so simply and convincingly?
You seem to be assuming there are no other equally or more plausible explanations for your three smoking guns.
1. The SBT: As I've stated, I think the SBT is problematical. And yet, umpteen panels, doctors and forensic types have concluded it is entirely possible. Others have, of course, disagreed. Any complex event has so many variables that a perfect reconstruction is impossible - the
precise location and angle of the rifle, the
precise speed and orientation of the bullet at initial impact, the
precise orientation of the limousine, JFK and JBC,
precisely what the bullet did as it traveled through and exited both bodies. The level of precision required to say the SBT is flat-out impossible seems to me flat-out impossible. So I assess the SBT in terms of all the other evidence pointing to Oswald and his rifle and chalk up the SBT to a problematic possibility (and perhaps not even essential to the LN position).
What gung-ho CTers never seem to consider is: If this was such a high-level conspiracy, how come the best the conspirators could do involved problematical things like the SBT and Magic Bullet and all the other red flags? This is the point I always make about the conspirators conveniently being geniuses half the time and idiots the other half. LBJ and Hoover and the Warren Commission and their minions couldn't have cooked the books better than this? I tend to think things like the SBT and Magic Bullet point in the opposite direction.
2. JFK's body: Is it not entirely possible that the shell-shocked Kennedy family and Admiral Burkley, who had been concealing JFK's Addison's Disease and other ailments for years, simply didn't want the body mangled by some unknown and possibly hostile Texas coroner? Is it not possible that even the Secret Service agents wanted JFK's body treated with more respect than this? On top of which, LBJ and Jackie wanted to be out of Texas now, and a Texas autopsy was going to delay that.
I see nothing sinister unless one is assuming that which is to be proven - i.e., that it was sinister.
3. Ditto with the limousine: The cleaning by Secret Service agents at Parkland was, I will grant, unfortunate but understandable. The car itself was impounded in evidence for weeks and the windshield that CTers love to speculate about was removed and provided to the Warren Commission. A six-member committee with representatives from the Secret Service, Army Materials Research Center, manufacturer Hess & Eisenhardt and Pittsburgh Plate Glass Company developed a plan to improve the vehicle for future use, and the plan was approved by the White House on 12-12-63.
Again, I just don't see anything sinister unless one is assuming something sinister.