1. No. IF LHO was the lone assassin, what was his motive? If he wanted attention (as Mark Chapman did for killing John Lennon) then why did he deny doing it? And why was the first shot so completely off target (not even close)? Deflected by leaves or tree branches? What proof do you have of this? Explain the hole in the windshield of the car (front to back), damage to the inside molding of the windshield, and injuries to all victims with 2 bullets? Why was the back of JFK's head missing if he was shot from behind? And you CANNOT have a back wound entering at C5 (cervical vertebra) location and exiting his throat as it's an upward angle. Impossible from 6th floor of TSBD.
2. Impossible to say, not enough evidence. Physical evidence from victims points to at least 2, one from behind, one from the front.
3. We know it was. Frames were "damaged." That meets your criteria. Apart from that, yes. Movement of people in limo is highly suspect as is the movement of limo itself. It contradicts testimony of witnesses as they said it almost came to a complete stop.
4. That's the real question, isn't it? We'll never know for certain, but we can get warm by asking who had to gain and then looking into the character of those people. Certainly wasn't Oswald! LBJ, oil people (Murchison, Hunt), Hoover, intelligence operatives (Morales, et al), elements of the mob and military. Such ideas were considered ridiculous years ago but 50 years later we know all these elements worked together as the need dictated. The simple fact is you can't have the VP involved in a conspiracy to take out the president. It would reveal too much about the true nature of the political system and how things are really done. It can happen elsewhere (and does), but not here. That's why the myth of Oswald still exists, because the truth can't.