But how is that different from ending up in Hermione's body via Horcrux?

How to resurrect Hermione when he gets around to it. After all, she has to become an alicorn princess!

Voldemort would not have given the properties to his body before now, because he had not had the Stone, and without its permanence effect, after a few hours the transferred properties would wear off.

He was overconfident in giving them to Hermione now, instead of to himself.

If Voldemort just gave Hermione a horcrux, how does he plan on killing her and using her for a horcrux.

This is a completely excellent suggestion.

Dumbledore, knowing that Harry was an expected pawn in Voldemort's plans, just booby-traps all the personal possessions that Voldemort would logically want to deprive Harry of, like the cloak, his wand, his pouch, his time-turner, Hermione's corpse...

In the same vein, booby-trap the Philosopher's stone. Coat it in a fine layer of contact poison, so that anyone who managed to retrieve it from the mirror and handled it with bare skin would get whammied. Then, if you actually win, wear gloves.

So what was the source of the resonance between Harry and Q?

Did I miss it?

I always assumed it was ritual magic, as arranged by Dumbledore and Lily, and performed by Lily.

But:

“James and Lily would have gone willingly to the death, if they had known.”

Which seems to imply that they hadn't known.

But it seems just way too convenient for Lily to just happen to fulfill the terms of a ritual, and it's unclear that V would have violated the terms by imposing his horcrux on Harry anyway.

At one time, I wondered if Harry was a time turned version of V, and that was the source of the resonance.

So what was the source of the resonance between Harry and Q? I went back to read the "while potion making" talk, but the source of the resonance seems to have been glossed over.

After reading comments in /r/hpmor, I've realized that Professor Quirrell has a superior move in the previous chapter, which has hopefully updated or will update soon.

Be honest, Eliezer; you just got sick of all the naked Harry jokes.

How I laughed when I realised it! When I saw you had made a Good Voldemort to oppose the evil one - ah, how I laughed!

I guess now we know what Dumbledore was laughing about in chapter 17.

The Cloak of Invisibility was torn away from him, and the shimmering black Cloak flew away from him, through the air.

Professor Quirrell caught it, and swiftly drew it over himself; in less than a second he had pulled down the Cloak's hood over his head, and disappeared.

Quirrell can escape the trap because he is no longer reflected in the mirror, being hidden by the True Cloak of Invisibility. All he has to do is walk out of the reflection, which he did.

Into the hand of the Albus Dumbledore flew from his sleeve his long, dark-grey wand, and in his other hand, as though from nowhere, appeared a short rod of dark stone.

Albus Dumbledore threw these both violently aside, just as the building sense of power rose to an unbearable peak, and then disappeared.

The Mirror returned to showing the ordinary reflection of a gold-lit room of white stone, without any trace of where Albus Dumbledore had been.

After reading Reddit, my interpretation of this scene is that Dumbledore realized Quirrellmort would not be affected by the trap, and that the only result would be that Harry would be trapped eternally outside of Time. Dumbledore makes a split-second decision to sacrifice himself in order to save the boy, throws the Elder Wand and the Line of Merlin Unbroken out of the mirror's reflection so that they will not be trapped with the headmaster, and trades places with Harry just before the Process of the Timeless (the rising sense of power) finishes. Albus Dumbledore is now trapped inside the mirror forever, and Harry Potter is back in the real room with Professor Quirrell.

How about a bullet? Make things appear like someone was the victim of an attempted murder, and have them "survive" with your identity hidden in them.

Clever idea, but currency doesn't stay long in circulation. Coins longer than bills -- the oldest bill in my wallet is from 2006, while I found a quarter from 1976 in my pocket. And if horcruces are as hard to destroy here as they are in canon, I imagine even Muggles would find it curious if a 50p coin were found intact after it should have been melted down.

I suppose it'd work if you're planning to keep supplies up on an ongoing basis and didn't think much of Muggle investigative abilities or their ability to interface with wizarding authorities, though -- and the latter does seem minimal in this universe.

How about the doorknob on the men's room in St. Paul's Cathedral? Or some other building you wouldn't expect to go away for a while. Or, heh, the Blarney Stone, if you can find enough time alone with it.

From chapter 107:

"Life-eaterss cannot desstroy me, I think," hissed Professor Quirrell. "And I will ssimply abandon thiss body if they approach too closse.