Conspiracy Theories?
I saw only one conspiracy theory in this film, the one claiming that Stanley Kubrick was involved in a conspiracy to fake a film of a moon landing.
The rest seemed to be pretty standard critical analysis of a work of art - not all that different than you might find relating to dissecting the works of Shakespeare or James Joyce, or any other artist who creates intricate pieces, that contain a lot of references and allusions to other works of art and history.
Kubrick made a lot of films that could be analyzed to the same extent that these people analyzed The Shining - Eyes Wide Shut and 2001, to me, invite a just as much discussion and analysis as The Shining, not to mention a lot of Kubrick's other films.