A plausible conspiracy theory?

[Jim Hawthorn]

If I thought I'd been duped into a stunt that turned into an assassination, I would've run to the nearest cop and blabbed my head off.

That would depend on how big the "stunt" was going to be and how much he was under their spell (death threats concerning his wife and family, etc.).
Perhaps Oswald knew that it was an assassination and his instructions didn't involve him being on the 6th floor.

I see him as too sharp to be duped into a stunt; his actions prior to the JFKA are difficult to square with a stunt; and his post-JFKA actions are impossible to square.

Unless he was doubling up, operating as an informant for the CIA.

We do have to account for the entire picture somehow, be it lone assassin or conspiracy.

A conspiracy only has to be more than one person - not necessarily a big inside job. It's not as black and white as that, and that is what clouds a lot of peoples perception of what happened.