Twilight accidentally walks into a boys bathroom.

Twilight Sparkle and Flash Sentry have a minor romantic interest in each other.

Sunset Shimmer bullies other students to get her way at one point she pins Fluttershy against a locker in a confrontational way.

Violence comes from the transformation scene

May not count but... the main antagonist (Sunset Shimmer) repeatedly uses insults ranging from mild to quite a bit stronger.

None.

The climax contains a transformation scene that may frighten young children.