In Star Wars, we see that becoming a Force Ghost more or less means the end of a Jedi's regular career. After Obi-Wan becomes a Force Ghost, he refers Luke Skywalker to Yoda for training rather than train him himself. After Yoda becomes a Force Ghost, he essentially does not participate at all in Rey's training, leaving that to Luke.
Can a Force Ghost train a Jedi student? If it is not possible, why? If it is possible, is there a reason why it is not done?
- Is it very difficult (or impossible) for a Force Ghost to provide proper Jedi pedagogy (e.g. in the way it is very difficult to teach quantum physics using nothing but pantomine)?
- Do Force Ghosts consider themselves retired from education and consider requests for training from new students to be highly antisocial, or at least something that is Just Not Done?
- Is there a policy forbidding this? E.g. Jedi Code Section 33 Subsection R Paragraph 27 Subparagraph V says that only a flesh-and-blood being is authorized to provide Official Jedi Training (TM) under penalty of Rancor Pit and having the student stripped of any Jedi rank obtained via said unauthorized training route? This could be sort of like how in our own world, people are often not allowed to sit for certain certification and licensure exams unless they have been trained by someone "authorized" by the test administrator to do so, regardless of what they actually know. E.g. if you didn't go to an officially recognized Medical School, you can't take Medical Licensure exams and thus have no way of becoming a recognized physician even if your brain is full of mad leet doctor skillz.