Majority of these questions seem to be Trivia, which can be looked up. I don't see any need to learn them. They are probably nice to know but are not helpful in objectively evaluating a developers iOS skills.

The important thing while talking to candidates is evaluating their understanding of technical concepts - like multithreading, GCD vs NSOperations, application lifecycle, properties, references, blocks, memory management, caches, sandboxing, responder chain.

Whats the point of someone knowing HealthKit or Voiceover or screen resolutions if they don't understand how atomic or nonatomic properties differ?