Originally posted by Demonic Phoenix
Did you miss the word 'ten'
The tenth is just the nine together in the Gedo Mazou.
Did he at any point have the TSB before activating his chakra cloak?
Precisely? Isn't the fact that TSB only appear once he activates the Biju cloak evidence in of itself that Naruto's SPSM is tied with his Biju power?
Where exactly did he combine the fragments and unlock Six Paths chakra just prior to meeting Hagoromo?
Him meeting Hagoromo in of itself was a result of him acquiring that chakra.
During his various near-death experiences earlier in the show, the Sage didn't appear before Naruto. He didn't even appear before him that time until Minato/Obito sealed Shukaku/Gyuki/Kurama into him. He appeared before Sasuke only after Sasuke received chakra from Asura's past reincarnation. These are tried and true methods of unlocking Hagoromo's chakra.
The databook explicitly states that 'Six Paths Sage Mode', a 'state', was given to Naruto by Hagoromo.
Judging from the paragraph you cited, though, the SPSM being described in the datebook is unique to Naruto; it possesses properties that Madara and Obito never had, and cites Light Style abilities.
However, we know that they still both achieved Six Paths Senjutsu Chakra and TSB just by virtue of being the Juubi's Jinchuuriki, even if they didn't possess the "SPSM" form specifically.
Coffin Seal is a different technique involving the actual Ten-Tails and Naruto is (obviously) not listed as a user.
I don't know why you're stuck on this, I never said Naruto could use the Coffin Seal. The Coffin Seal is a method of subjugating the Ten Tails; Naruto was willingly given chakra by the Tailed Beasts.