I rarely post a crossword clue but I think i'd probably put it in the main Q&P category because I think that is the one most fans of quizzes, puzzles and crosswords go to. If all crosswords went into Crosswords i think that there would be very little in the main Q&P category.
It's the same with Law (should normally either be Criminal or Civil), Media and TV, ( should go under radio or TV), Business and Finance (should be Business or Personal Finance).
Does it cause a problem? I know Q&P tends to get full of crossword questions at weekends, so maybe what we really need is a separate subsection for Quizzes or Ditloids