Crazy Mode is very risky. This mode is capable of breaking your saved game. Consider using a copied character before enabling this feature.
Crazy Mode is just that: Crazy! It allows you to attack/kill any NPC in the world, and I mean ANY. Quest givers, skill teachers, anyone. I would not advise using it unless you wish for a little extra gold or EXP.
You could possibly kill every NPC in the game, resulting in not learning any more skills and not gaining any more quests to accomplish. You have been warned. The NPC cannot respawn!!!