I got the sense that Luke may have given the old Jedi texts a cursory glance but never really read through them carefully and thoroughly. That's what I got from his reaction when Yoda asks, "Read them, have you?" In any case, they didn't actually get destroyed in that fire. Not long after, we see that Rey had already managed to swipe them all and stow them away on the Millennium Falcon. Those scavenger skills at work!
From what they wear, I would assume Vader oversees the inquisitors, if there wasn't a Grand Inquisitor.
The Emperor is the Sith Pope, so Vader is a Sith Bishop?
There must be other classes of Sith than just the inquisitors.
(Google says that there was a rich stratified sith culture during the old republic, but not so during the imperial era.)
How can it be a secret that the Emperor is Sith, if Vader is out?
If Sheev is out, then Sith should be the official state religion even for non force users... Unless Palpatine believes in freedom of Religion? Y'Know except for Jedi.
In the original trilogy days, the nature of the Sith was kept vague and mysterious. Fandom only knew there was such a thing as Sith from tie-in materials. The word "Sith" was never actually spoken in dialog in the final cut of SW77. Tagge's line from an earlier version of the Death Star conference room scene, "This Sith Lord sent by the Emperor will be our undoing," didn't make it into the movie (also in that version, Prowse-Vader spoke of "The Cosmic Force").
In-universe, I think the galaxy at large is kept in the dark about the extent of Sith influence in the Imperial era, and exactly what the Sith are. Specialists in ancient history might have some awareness that there was once a bigger Sith religion, and that there were ancient Sith empires, but on the surface the Galactic Empire doesn't look like those. It appears to be a "secular" totalitarian dictatorship, even to those in its own top ranks. Anything having to do with "The Force" is a dying throwback to olden days. Admiral Motti derided Vader for his "sad devotion to that ancient religion." Would he have spoken that way if it was well-known that the Emperor himself was the foremost practitioner of said religion? Maybe if the Emperor was also generally believed to be some secluded figurehead who didn't do much, like the novelization of the first movie indicated. "Fine, let His Highness keep occupied practicing that old religion in his palace while we actually run things and build our own power."
Even Tarkin, who worked alongside Jedi during the Clone Wars, apparently considers all that Force stuff to basically be the same thing, as he tells Vader, "You, my friend, are all that's left of their [the Jedis'] religion." I can't remember if it was in one of the recent books or comics, but I seem to recall someone remarking that, to the rest of the galaxy, Jedi and Sith are like different denominations of the same religion, using this cosmic power of theirs to have power in the galaxy without real regard for everyone else. The top dogs in the Imperial army/navy are aware of a handful of believers in "The Force" who work as Imperial enforcers, but in those officers' eyes it seems that such practitioners are generally "kept in their place," unlike in the old days of the Republic when thousands of treasonous Jedi were allowed to run loose, unchecked, and their evil order nearly overthrew the government.
Kor
