It’s not jutsu, period. For example, the Sharingan’s Pre-Cog or ability to see Chakra are not “Jutsu”. They are inherent qualities of the Sharingan. “Jutsu” in this case, would be Koto, Tsuki, Susanoo, Kamui, etc.
So yes, you are drawing a false equivalence when you attempt to assert inherent qualities are “Jutsu” here. It is not.
Except we literally see him do just that as well as Absorb Nine-Tails Chakra. You point is invalid.
Via Madara’s example, we know doujutsu abilities are not erased from the user’s catalog of abilities, just diminished. He had no Rinnegan but was still SHOWN using a diminished version of Preta. You literally have no standing here and I suggest you reread those parts of the war arc before continuing.
Wrong. Read above.