Consider that you're arguing that JFK got shot in the head and did nothing more than raise his arms to his neck.
Consider that you don't explain what happened to the bullet. [
emphasis added - this is the only point you choose to address in your subsequent post. You ignored everything else.]
Consider that the image on the Zapruder film (which depends on the exposure setting) has nothing to do with what people saw. It was a bright sunny day, just after noon, which would have been near-optimal viewing conditions for eyewitnesses. The "lighting conditions in Dealey Plaza" don't help your argument whatsoever.
Consider that you don't know the map directions in Dealey Plaza. "Northeast" is almost directly behind the limo in the Zapruder film. The sun was high in the southern sky, and the limo passengers were facing it, putting the northern part of their bodies in shadow. The 'eastern' side of the passengers & spectators would be the side mostly away from Zapruder's camera.
Look at a map:
https://cfrankdavis.files.wordpress.com/2013/08/jfk-dealeyplaza.gif
(north is denoted on the Main Street portion of the map. You can see the limo was proceeding in a south-westerly direction during the shooting).
Consider that the sign in question didn't block all the spectators view of JFK during the early part of the shooting - or even most of them. Or even a significant minority of the spectators. Any of those spectators on the east side of Elm (opposite Zapruder) didn't have the sign blocking their vision, nor did most of the spectators on the west side of Elm. Only those near Zapruder would have their vision blocked by the sign at approximately the same time as Zapruder.
Consider that you are citing the lack of evidence for a wound in JFK's hairline as evidence for the wound in JFK's hairline, telling us how difficult that wound would be to see. I remind you the more likely explanation remains that no one saw that wound because there was no such wound.
Consider that your listing above is pretty much a meaningless jumble of non-evidence, suppositions, and outright errors of fact. Consider that is why we don't find your arguments convincing.
On the question of where this earlier hypothetical head bullet ended up, the only logical answer would be that it exited the throat, without invoking alteration or high-tech ammunition. Remember that JFK chest X-ray what shows a cavity filled with air going from the middle neck to the anterior throat area? The one that Lattimer swore represented a bullet track but totally could not be evidence of a single high-velocity round entering the back and exiting the throat?
2. Please explain, using your apparently vast knowledge of firearms, what you mean by high-tech ammunition as it would have existed in 1963.
I think it was Francis X. O'Neil or James Sibert that said during the autopsy, the possibility of high-tech ammunition was being investigated before they just settled on the undercharged round hypothesis. Bullets made of wax, ice, plastic, were suggested. I understand that bullets that dissolve into a very fine metallic dust existed.