(ii), continued. The universe is threatened in The Year Of The Ransom (see here) and, more generally, the Patrol exists to prevent cosmic chaos (see here).
In Operation Chaos, Steve Matuchek broadcasts telepathically to other universes because there might be a multiversal threat.
(iii) This line of thought was started by reading a comic strip but it was Logicomix, not a superhero title. The philosophers' quest is to verify reality but, to do this, they must struggle not against supervillains or time criminals but with intractable and intangible concepts.