1. Yes. Not many teachers truly understand details about jhanas. Of course, these details have been hidden for many centuries until Waharaka Thero made self-consistent explanations.
– There are Ariya jhana (kama raga ELIMINATED) and anariya jhana (kama raga SUPPRESSED)
– Then there are jhana and jhana samapatti.
2. When in a jhana, jhana citta DO NOT run continuously. So, in effect one goes in and out of jhana. That is why one in a jhana can see, hear, etc.
– But when in jhana samapatti, jhana citta run CONTINUOUSLY. Thus, one in jhana samapatti CAN NOT see, hear, etc.
3. Jorg wrote: “also a story from the sutta when a monk got “cremated” in the forest, and was seen later in the village by the people who cremated him because they thought he was dead..”
– That is an account of an Arahant who was in Nirodha Samapatti. That is a special case of a samapatti. One needs to get to the highest “arupavacara jhana” AND be an Arahant to get to nirodha samapatti.
– The body of someone in nirodha samapatti can not be destroyed.
4. Jorg wrote: “However, he teaches to get into jhanas via breath.”
– That is unfortunate. Breath meditation can ONLY lead to anariya jhana.
5. I suggest reading the new post that I just posted: “Rāga and Jhāna – Two Commonly Misunderstood Words”
– It has more details and links for further details.