I am not saying that LBJ took part in a conspiracy, but at the best, he didn't really give a flip who killed Kennedy. There are other possibilities, including the fact that if a conspiracy traced back to Castro, that would lead directly to Russia, and war.
That said, the big flag to me is Ruby making the equivalent of a suicide hit on Oswald. Why would a Jewish mob guy that runs a strip club do this? I mean he HAD to believe he would die that day. Would you expect to shoot someone in front of a room full of armed Dallas cops (with the attitude they had in 1963) and not get shot down?
All this aside, I think other people were involved. No clue as to who, where, how, why, but Dan Rather believes Oswald acted alone, and that's enough to convince me there was a conspiracy.
In actuality, we'll never know what actually happened. Too much was covered up then, too many false leads planted, too many bozos doing the investigation, too many amateur sleuths tracking through the information.
Agree with all of your points - there’s a youtube video of a journalist who swears he saw Ruby at Parkland on Nov. 22. Later the Warren Commission insisted that the journalist was mistaken and he obviously was confusing what he thought he saw with what he actually saw. Or something like that. But the journalist says that he knows what he saw and he saw Ruby? Does that prove anything? Obviously not. But I tend to agree with you that Ruby is a key player and the stated reasons for doing what he did don’t really add up.