Buster Moon: Why aren't you rehearsing?
Frog: I'm through! They said I'm an intolerable egomaniac. I don't even know what that means.
There's no way that Eddie and Nana left the flooded theater without getting a single drop of water on them. The water flooded up to the ceiling and there's no other way to exit besides the front doors, and Moon's secret exit, which also floods. They do not leave through either way.
When Moon is riding his bike in the beginning of the film, he crosses a bridge, and we can see a whale wearing the bowler hat from "Meet the Robinsons."