For some reason I was thinking Harry was under his invisibility cloak until pretty much everyone involved in that charade was unconscious. Am I misremembering?
Would you consider the story ending with Voldemort, up to that point presumed dealt with, suddenly showed up and killed Harry with no chance for recourse?
It would be a quick resolution, but despite what Harry thinks as he matures, he is in fact living inside a narrative. I don't believe that the story would end on such a down note. I could well be wrong, but that is what I choose to believe.
Yeah it was resolved when Dumbledore revealed that he was the one who gave it to Harry to Snape/McGonnagle. Snape reported to Potter that he used it and it went to an empty house in London.
Harry at this point trusts Hermione's judgement far more than his own. Putting Hermione in the position of power as the girl-who-lives-again pushes her into the forefront, letting her be the head that Magical Brittain needs, leaving him to go about his business determined to not destroy the world, as his unbreakable vow requires.
I'm sure he realizes it, but Harry literally obliviated everything in his memory, which would presumably include knowledge of any anti-obliviation counter measures (like the signals that were mentioned early on).
Unless there's some spell or artifact we haven't heard of before now that blocks/reverses Obliviation, I am going with it worked. And from a meta perspective, we know the story is winding down, so Voldie coming back with his full memory and then having another showdown with a different solution seems highly unlikely.
That sounds entirely too much like Dune to me. That's enough reason for me to doubt shields work that way.
Unless they award the points in response to Voldy being killed by Hermione. Which means even in dying, Quirrel wins.