one of the monsters has the ability to heal wounds by peeing on them other than that nothing

A man in sprayed in the face with some sort of acid. He's later shown being carried away on a stretcher.

A boy gets a bloody scrape on his knee. He's immediately healed by the aforementioned monster.

A submarine is blown up by a monster.

A monster rampages through a city. Actual on-screen destruction is barely shown, save for a scene where the monster levels an empty school building.

Mothra and the monster engage in a lengthy fight for a large portion of the movie. Nothing graphic is shown during these fights.

A single use of "damn" in the English dub.

Dagahra may be frightening to certain younger viewers.

Belvera chases a group of children through the forest in an attempt to kidnap Ghogo from them. This scene is rather tame, however.

A pair of men aggressively threaten the group of kids for the same reason later on.

SPOILER!: there is a scene where mothra is almost killed this may upset younger viewers