Harmony can best be described as the relationship of pitches.

The distance is the answer your looking for. hope i helped you!

Yes and no because if you know the vocabulary used you will understand it and go faster but you might not need it

Personally, i think the games do because it's actually them controlling it. this might cause them to think it's okay to do it for real. as for animated movies i think they are mostly fine because they're animated. also, animation has come a long way causing animated movies to become more real but 30 years ago this wouldn't be as big of a problem as today.