I would also be interested to know if their is anyone who is a Gnostic and has studied the original Shinto as well. That part quoted was the only part I ever found that Samael ever mentioned about Japan and it's culture. There is also nothing mentioned on Amaterasu or the demons that have many many stories about them including the parade of a hundred demons, or the esoteric meanings of the symbols seen of the mirror, magnatama and various ceremonial dances preformed by the priestess's, ect. Motohisa Yamakage has some great books on shinto as he was taught the version that was passed down through ancient lineages via word of mouth, sadly only his one book is translated into English. Nowadays most of shinto has been taken over by egomaniacs and remade by people claiming to be the founder of such and such shinto.
Again if there is anyone out there studying any of this I would be super interested in learning more as I have always been drawn towards japan and it's culture.