In no particular order:
The fact that the Stemmons sign obscured JFK and JBC from Zapruder's view while C399 was hitting both of them
The fact that Oswald missed the limo altogether with his first shot, but hit JFK on both of the following, farther-away shots
The fact that Dealey Plaza was a virtual echo chamber and caused many of the witnesses to mistake the number of shots and the number of seconds between them
The fact that JFK was sitting and wearing a tight and rigid corset which amplified his upper torso's "back and to the left" movement when the fatal bullet ripped through his brain (from behind) and caused a catastrophic neuromuscular reaction
The probable fact that the missed shot's hitting the traffic light mast arm caused the bullet to lose its copper jacket and therefore leave no traces of copper in the smear it left on the curb near James Tague
The fact that neither the Parkland nor the Bethesda doctors shaved the hair off of JFK's head to better reveal the nature of the fatal head wound.
Several of your "the fact that" statements are simply wrong. But, beyond the factual errors in your list, I find your posturing curious. You declare that people who believe Kennedy was killed by a conspiracy are tinfoil hatters. This is an interesting posture to assume given that you are in the decided minority of Americans who believe the lone-gunman theory. According to the most recent polling data we have on the subject, about 62% of Americans believe JFK was killed by a conspiracy, while about 34% do not, with about 4% undecided.
Furthermore, the last government investigation into the assassination, the House Select Committee on Assassinations, concluded that Kennedy was probably killed by a conspiracy, that there were four shots fired, that Jack Ruby had significant Mafia ties, that Ruby lied about his reason for shooting Oswald, that Ruby's shooting of Oswald resembled a Mafia hit to silence a witness or conspirator, that the WC ignored the clear weight of the evidence regarding how Ruby entered the DPD basement to shoot Oswald, that someone helped Ruby get into the DPD basement, that the DPD left doors unlocked along Ruby's route into the basement, that the DPD removed security from the area of the garage nearest the stairway that Ruby used to enter the basement shortly before Ruby entered the basement via that stairway, that someone was moving boxes in the sixth-floor window within 2 minutes after the shooting (obviously, it could not have been Oswald), that Silvia Odio's account of meeting with Oswald in company with two anti-Castro Cubans at a time when Oswald was supposedly in Mexico City is credible, that the committee established that Odio told several people about the Oswald visit before the assassination, etc., etc.
Finally, here is a very partial list of the "tinfoil hatted" public figures and experts who are on record as believing Kennedy was killed by a conspiracy:
* Dr. Joseph Dolce, an Army wound ballistics expert who played a leading role in the WC's wound ballistics tests.
* The late Senator Richard Schweiker.
* Senator Christopher Dodd, who served on the HSCA when he was a member of the House of Representatives.
* The late Senator Richard Russell, who served on the WC.
* Dr. Roger McCarthy, a ballistics expert with Failure Analysis, which assisted with the American Bar Association's mock Oswald trials in the 1990s.
* Robert MacNeil, formerly of the McNeil-Lehrer News Hour on PBS.
* Ambassador William Atwood, former Special Assistant to the U.S. delegation to the United Nations.
* President Lyndon Johnson. (We now know from the Johnson White House tapes that Johnson rejected the single-bullet theory. We also know from former Johnson aides and associates that privately Johnson said he believed Kennedy was killed by a conspiracy.)
* The late Dr. Milton Helpern, a renowned forensic pathologist and formerly the medical examiner for New York City.
* The late Dr. John Nichols, a forensic pathologist and formerly a professor of pathology at the University of Kansas.
* The late Carlos Hathcock, a Marine sniper who was widely regarded as the greatest sniper of the 20th century.
* The late Evelyn Lincoln, who was Kennedy's White House secretary.
* The late Dr. George Burkley, Kennedy's personal physician.
* Former Vice President Al Gore.
* Former Senator and Secretary of State John Kerry.
* Kennedy aides Dave Powers and Ken O'Donnell.
If anyone is wearing tinfoil hats, it is lone-gunman theorists.