As I recall, only the first Crusade was endorsed by a Pope. And no, the teachings don’t change, though the way things are phrased varies based on culture.

In a manner of speaking, this is correct. A Christian’s home is in Heaven, they simply travel here as immigrants.

College of Cardinals gather to vote on who replaces the Pope. No one over 80 is allowed to vote.

Only in matters of faith and morals, only when speaking “ex cathedra”, and only when defining a matter for the whole Church. If the Pope says the sky is greeen one day, Catholics everywhere should start asking when the Pope last took his meds, and not claiming that the sky is green.

To my knowledge, these conditions have only been met a few times in Church history.

This is where either a recent KISS fork or Gentoo comes into play…