I have vague memory that there were similarly styled hairstyles for the same character in Candy Candy and I always thought either that was the origin, or some other Pride & Prejudice-y era portrayal of 'mean girl'. Wouldn't be able to point at a specific show/movie name for the latter, though.

All the benders have the potential for dirtbaggery, but the equivalent for Waterbenders (bloodbending) is pretty bad and taboo and robs people of their autonomy, so: Yes?

It's weird feeling like I know a surprising amount of trivia about a show I only caught snippets of when it first aired.