Stanley Kubrick's "The Shining"

Tonight was the sixth night of the Stanley Kubrick Film Series that I've been hosting this winter, and the feature film was "The Shining". This is only my second viewing, and it's been a while since I've seen it. The story contains a number of ambiguities that I want to understand but seem unable to figure out. What is the significance of the picture at the end of the film? While it does clarify Grady's statement earlier in the film in which he tells Jack that he's always been a caretaker, it opens the door to the possibility that Jack himself is a ghost or some other kind of manifestation of the hotel itself. But then did Jack's entire life up to that point contrive to get him to the hotel to kill his family? Another unclear aspect is whether Jack has "the shining" just like his boy. If he does, he is unaware of it and unable to relate to it; or maybe the hotel is simply taking over his mind? Danny's state of mind was unclear to me as well: he obviously has some sort of ESP but he also seems to have developed a sort of split personality in his friend Tony; it's as if Danny's been seriously traumatized (perhaps from his father dislocating his shoulder?). When Tony takes over Danny's mind late in the movie, it makes me think of a person who has slipped into survival mode, yet it also seems more than just a psychological defense mechanism. Somehow it's related to his ability to sense what's going on beyond his senses. And what on earth does the shot of the man with the person in the bear costume supposed to mean? It truly is bizarre, but I appreciate the insertion of a bit of humor into a tense scene. :) I have not read the book, and my understanding is that Kubrick's version is a bit free with some of the details. Perhaps a read through King's novel would shed some light on the film, but then again, Kubrick has a knack for ambiguity. Despite all the details that I haven't made sense of, I immensely enjoyed the film and look forward to seeing it again.