Well, when you're making a crossword puzzle, it's not really for the "general population" but for the people who enjoy crossword puzzles. There's a wide range of degree of difficulty, ranging from the very easy Monday puzzles typical of, say the Los Angeles Times, and the sometimes nearly impossible themeless Saturday Stumper in Newsday. Editors select puzzles from their submissions based on how they fit (if at all) into their portfolio, and they quite often tweak the clues of puzzles so as to fit better for the audience they're targeting. Sometimes they request revisions to change words in the grid that they don't want to use. So, don't let that uncertainty hold you back - once you've started getting feedback from editors about your submissions, it will all start to fall into place.