Do you not see any issue with this being used for an actual, graded quiz and a student being kicked out because they thought pressing Alt+F4 would give them an advantage? It's not like they were funny but unrelated and harmless hints. They were not obvious jokes to non-technical people, and could directly harm the students if they took them seriously.

You can throw all the Alt+F4 and Ctrl+W jokes you want into a game. No harm, no foul. But they have no place in an application like this.