I have a slightly different explanation for the instant skillz thang. Some Force abilities are natural to people strong in the Force. Little Annie had fast reflexes and prophetic foresight, Leia seemed to be able to sense danger and could read telepathic messages from Luke. Kylo had more training than Luke got from Ben or Yoda. Touching the saber triggered in Rey a series of dream images which were about the object but also about herself. This may be enough for her to telepathically scan Ren to learn the mind trick and even absorb his sword fighting skills from him but not being such a hissy queen as Ren meant she could use his skills with more discipline. Luke enters the cave and comes out with a insight we prevents him from giving into Vader.We don’t learn anything in the original films or prequels that contradicts Rey gaining knowledge from a connection to an object. A cave is an object. As for being critical of a film based on premise details alone, I have still yet to see The Sixth Sense because someone explained the basic set up for me and I predicted much of the film and the twist. It just seemed so obvious to me that I didn’t want to watch a film so easily decodable.