BloodyShrimp

I think these are sufficient evidence that this is the real Dumbledore, not the mirror showing Quirrell what he wants.

The sense of doom. I thought the magic-can't-interact was mostly just the strongest edge of that--e.g. (maybe "i.e." too) their magic could interact but it would hurt them enough that they don't try.

That could just be a feature of the True Patronus, which is pretty anti-death and especially anti-indifference-to-other-people's-lives.

Your point 2 is another thing I'm getting pretty suspicious of. Quirrell has set up a very long plan, and could easily have faked this effect with wandless magic, or an enchantment he could later dispel, all along.

Certainly, and in the actual situation, I would have done worse than he actually did. But, this kind of armchair analysis is extremely enjoyable, and a good way to improve your in situ skills.

This is similar to choosing strict determinism over compatibilism. Which players are the "best" depends on each of those players' individual efforts during the game. You could extend the idea to the executives too, anyway--which groups of executives acquire better players is largely a function of which have the best executives.

Efforts are only one variable here, and the quote did say "largely a function of". Those being said, look at how often teams replay each other during a season with a different winner.

Mentioning a similarity to past successful decisions seems like it qualifies as "constructing a more contextually specific argument than 'you'll understand when you're older'".

While this is on My Side, I still have to protest trying to sneak any side (or particular (group of) utility function(s)) into the idea of "rationality".

But the map is the map...