Twilight and Flash Sentry share a few intimate moments (hugs, looks,)

The songs sung by the three villains "Battle of the Bands | Under Our Spell | Welcome to the Show" are pretty suggestive for a children's movie; among them are hips moving and dance numbers. In 'Battle of the Bands' the lead singer touches people's heads and cheeks throughout the song.

It could be unintentional, but at least one time each, Rainbow Dash's and Sunset Shimmer's breasts are momentarily larger than usual. It might happen to more of the characters, but I only noticed it with those two. They're quick and hardly noticeable scenes. If you aren't looking for it, you probably won't see it.

Minimal violence. The Dazzlings plot to take over by brainwashing the students with their music, which makes them angry and argumentative. No gore.

None. The only thing close to it is Rainbow Dash and Fluttershy mentioning "kicking somebody's butt".

Minor insults.

Not sure if it counts, but when people are bickering back and forth, a green haze forms at the ground. The sirens, or Dazzlings, then adsorb it through their red amulets. The green mist is a physical form of disparity on which the sirens feed and gain power.

The final battle between the sirens and the Rainbooms may scare young children with the various transformations by the antagonists (who become ethereal dragon-like creatures).

The transformations of the Dazzlings into Sirens may be frightening to younger viewers.

The sequel as a whole, (Villains more mature, added with deeper motives and songs,) is a lot darker for a 'G' rated movie, in comparison to the prequel.