15 letters Question asked regarding two red-carpet photos of those named in the starred clues? Answer: WHOWOREITBETTER
15 letters Immediately ... or where this puzzle's five shaded squares appear? Answer: ATTHEDROPOFAHAT
15 letters Take apart in order to reproduce ... or a hint to what's hidden in 17-, 23-, 34- and 46-Across Answer: REVERSEENGINEER
15 letters Long-running western anthology, the only American TV series with its three initials Answer: DEATHVALLEYDAYS