The grand hilbert hotel is a metaphor about infinity. If a hotel has an infinite number of rooms, it will have enough room for him. If every room is full, they can all still move up by one room number. Infinity means you can always shift everyone up by 1 room number.
The ship of theseus is a philosophical question about whether it's still the same ship after having every board and nail in it replaced over centuries of repairs gradually replacing all of its parts.
Asking if Sisyphus is happy is a reference to a famous Albert Camus (French absurdist philosopher) quote "One must imagine Sisyphus happy"
Using numbered lists is a common tactic in debates and other public speaking when you have prepared talking points you want to hit.
Basically it's a mnemonic technique to help make sure you list all of your best points/pieces of evidence. You list them in the same order every time so that to recall the next point on the list you just need to remember the overall topic and the number that you're on. That way it's easier to contextualize the memory and retrieve it consistently.