Quirrell likely cares about the effects of the grades and not so much about whether they are fair.

Not that it matters, but I don't really understand Quirrell's grading criteria. Is Neville's score 'outstanding' because he alone made the sensible move of escaping to safety of his home from life-threatening dangers of Hogwarts and Hermione's grade low because she failed the 'ultimate' test? If so, does Harry's surivival to-date 'exceed' Quirrell's expectations?

Alternatively, is Neville's score a reflection of his rate of improvement over the term, which admittedly was outstanding, relative to Harry's (or Hermione's)?

Perhaps, grades other than OWL's and NEWT's do not matter academically, so Quirrell's grading is purely subjective/random?

Some of these have been explained / fired already. I think most people agree that:

• Sirius Black is not Hat and Cloak, because H&C was Quirrel; I think this is pretty definite.
• Traps on the third floor are an obvious trap for a Dark Lord foolish enough to try stealing the Philosopher's Stone, which Quirrel is not, because he realizes it isn't there.
• What Dumbledore wrote in Lily Potter's potions book was advice she used to help her sister. Which was a risky, stupid, Griffindor / Dumbledorian thing to do. The horrible secret is that not that Dumbledore sneaked into the girls' dorms at night (presumably he found a different opportunity to write in the diary) but that Dumbledore caused Lily to help her sister, which caused Petunia to marry Professor Michael Verres-Evans instead of Vernon Dursley, even though a centaur told Lily doing this would cause the world to end, which is now about to happen. And this caused the HP:MOR universe to branch from the canon Harry Potter universe.
• There's nothing interesting left in the Chamber of Secrets, because the Dark Lord killed Salazar's snake and removed any portable artifacts.

I thought "destroying stars" was pretty simple: Dyson spheres. That's not actual destruction per se, but from a Centaur's perspective...

Has anyone compiled a list of Chekhov's guns that haven't been fired yet in the story so far? Off the top of my head, I have:

• Bacon's diary
• Bellatrix Black
• Sirius Black (incidentally a candidate for the Cloak and Hat, who possibly knows limitations of the Marauders' map)
• Traps on the third floor
• Significance of Dumbledore writing in Lily Potter's potion's book
• Lesath Lestrange
• Harry's 'shopping list' given to Gred and Forge
• The missed glint in the Godric's Hollow graveyard
• Chamber of Secrets / Salazar's snake?
• Secrets of spell creation (which Quirrel is so keen on keeping away from Harry)

Anything else?

the current time/reality in which Hermione is irrevocably dead will be destroyed as a result of Harry deciding to change the fact.

Harry himself appears to be pretty firmly set against that:

"And while I hate to get all PHILOSOPHICAL," Harry desperately tried to lower his voice to something under a shriek, "has anyone thought about the IMPLICATIONS of going back six hours and doing something that changes time which would pretty much DELETE ALL THE PEOPLE AFFECTED and REPLACE THEM WITH DIFFERENT VERSIONS -"

So I wouldn't say never, but I think it would take something extraordinary, considerably more so even than Hermione's death, to drive him to that.

I cannot think realistically what Harry can do to threaten his 'modified' interstellar probe at present time unless he can prevent it being modified (horcruxed?) to start with, i.e. go back in time.

At the time Quirrell begins his freakout, he doesn't know what form it will take, either. He just heard that "HE IS THE END OF THE WORLD" and that's all he needs to know. He may get clued in a bit more later on, when he overhears Firenze talking to Harry. Clearly, Harry is going to acquire a massive amount of power he doesn't already have, but I don't see any particular reason to promote the option of super-duper-time-travel to the fore.

Hypothesis:

• The prophesied 'end of the world' will involve meddling with Time.

Some semi-random observations/conjectures supporting the hypothesis:

• The 6-hour information transfer limit is tied to the Interdict of Merlin. A 6-hour timeframe seems rather arbitrary in terms of describing a purely natural constraint of the underlying physical reality. It makes perfect sense, on the other hand, as a human-designed complementary measure of enforcing the Interdict as otherwise wizards would be traveling back in time to learn from old masters before their deaths, thereby negating the Interdict.

• The whole plot generally revolves around paradoxes and uses of Time. Atlantis is supposedly 'erased from Time' (not destroyed). Hogwarts castle's random changes have time patterns (certain years and days in the week). References to students getting lost and coming back as old men or going higher than the castle's highest level (implying shifting passageways transporting people into Hogwarts castles in some alternative times/realities?).

• Repeated allusions to Harry destroying stars is unlikely to be referring to a literal physical annihilation of all visible stars. I would place a much higher probability on the possibility that the current time/reality in which Hermione is irrevocably dead will be destroyed as a result of Harry deciding to change the fact.

• What spells are most likely to be declared so dangerous to warrant the Interdict? No magic (aside from Time travel), no matter how destructive, comes even close in my mind to justify Merlin sacrificing himself to impose this rather oppressive restriction that limits indirect information exchange of ALL wizards in ALL of time, present AND future!

• The first time we hear Quirrelmort's inner monologue is when we learn that he is honestly afraid of what Harry will do. I cannot think realistically what Harry can do to threaten his 'modified' interstellar probe at present time unless he can prevent it being modified (horcruxed?) to start with, i.e. go back in time.

• Time paradoxes are ruled out. Why? Because reality is somehow ensuring consistency? But then, how could Atlantis 'erase' itself from Time? I assign much higher probability that this restriction is designed as part of the Interdict again rather than a naturally occurring phenomenon.

Thoughts?

given the premise that souls do not exist

Do you mean that this is the premise of your analysis, or a premise of the HPMOR universe? Because if I understand correctly, all we have to show for the non-existence of souls is Harry's (entirely rational) belief, which may yet be challenged by future observations.

It is still unclear how horcruxes would fit into the HPMOR universe given the premise that souls do not exist. Here are some thoughts and conjectures revolving around the postulate that horcruxes are complete memory/personality backups:

1. To recreate one's identity, there has to be more than just replication of memories. There also has to be a way to replicate the 'software' that governs our thought processes. Removing the limitations and shortcuts that our physical brain has in place would undoubtedly remove lots of mental biases (making us hyper-rational) but also raise the question of whether the resulting entity will really be 'us' or just well approximated copies of us (a well explored topic in the transcendent pony fic).

2. The very possibility of possession (as evidenced in the zombie Quirrell) gives evidence in favor of the possibility to project one's mind outside one's original body and still be able to retain the capacity to not only have semblance of life (a la magical portraits and ghosts), but to also be able to learn new information and retain it (i.e. grow) and interact meaningfully with the environment.

3. Assuming away the whole issue of whether one's identity can be virtually encapsulated independent of our biological hardware, this would require careful copy control (lest there be multiple versions of you running around, raising the question of which one is the 'real' you, explored comedically in one of robst's fanfics). Is Harry an incomplete horcrux, retaining Voldemort's post-transcendent software (hyper-rationality), but not his memories, i.e. a failure of copy control? (He clearly didn't inherit his rationality from biological parents?)

4. Magic in potterverse directly interacts with mind. So magic is capable of storing information, including memories, software, etc?

Since Voldemort has already gone through the process, he already knows what's involved.

IMHO wearing metal armor is a brilliantly canonic tactic.

My first thought when I finally figured out that the metal was about mundane armor and not something crazy like transfiguring muscles was 'why don't Aurors wear impressive clanking armor, then?'