Questions such as "Have you ever considered getting a man-bun?" and "Is a spray tan ever a good idea?" might be a bit less controversial. It would certainly weed out a significant bunch of people who, whilst not in and of themselves convicted felons, really ought to be locked up.
And if you want to encourage ethnic diversity, how about "Where are all the white women at?"
Another good one - "Why the hell do we spell colour like that?". A bit of a logistical challenge, which also would encourage people to research international matters.
Also, "Foreign Affairs. Are they a good idea?" could be quite thought-provoking for some.