<spoiler>For #1, I didn't hear correctly because I didn't understand that the clearly insane and cruel warden would let the prisoners label the boxes before hand :-/
You need a minimal perfect hash function but it's a thing that can be done, especially because prisoners in these sort of conundrums always have fantastic memories and mental math facility.
https://en.wikipedia.org/wiki/Perfect_hash_function#Minimal_...
If you assume the axiom of choice and allow them to memorize arbitrary uncountable elements, you can get more interesting puzzles (and also go insane).
https://cornellmath.wordpress.com/2007/09/13/the-axiom-of-ch...
The problem statement makes it clear they can communicate prior to starting the game.
Me: "Here's a plan that will defeat the werewolf in any case, even if I am the werewolf"
Them: "That sounds complicated, therefore suspicious, let's hang him"