There was a time when I was one of the people that believed in the conspiracy theories. I disbelieved the single bullet theory, that Oswald was the lone gunman etc. But I got into researching and reading everything I could about it and over time I became convinced that Oswald was the lone gunman and he fired the fatal shot that killed Kennedy. One thing that convinced me was looking at other cases and how no case is ever clean, meaning the facts all fit so nicely into place. Even with cases that are open and shut there are these little details that don't seem to fit the picture. That's because things don't happen like that. The world is really a series of chaotic events where so many things happen simultaneously that it is impossible for anything to be straightforward. Conspiracies are borne of this imperfection.
The people close to Oswald said he was unstable and they were afraid he could explode at any time.
Of course this does not mean Oswald was not part of a conspiracy. I don't think we ill ever know for certain is he was working with others, or used as a patsy. I don't think so, but I cannot say with 100% certainty. I don't think the government was involved. I think if it was the government, someone involved would have taken the money and written the book by now. I don't think it was Cuba or Russia either. I don't think either of those government would have used someone like Oswald. To much could go wrong.
If anyone, I would say it was the Mafia. First, the Mafia knows how to keep a secret. Second, the Mafia would use someone like Oswald to keep a safe distance from the shooter, AND they would take out the shooter to keep him quiet. I don't think they would involve a wannabe like Ruby though. Plus Ruby died of cancer in prison and never confessed. Seems to me he could have copped a plea if he had something to say.