@K9mutt A translation suggestion/correction:
P.7 : "So it's strange that there weren't more people there, right?" should really be "Even though it was good, I wonder why no one else went to see it." What you had kind of implies that there were SOME people there, instead of none, when the Japanese reads 「面白いのになんでお客さんいなかったんだろ」which has a literal translation of "even though it was interesting, i wonder why there were no customers there." What you had blunts the intended impact a little bit.
Also, I don't think there's any specific movie being referenced. It sounds like a generic jokey line that shows up in comedy bits intended for children's audiences (unless, like you said, it's a self-reference to the movie (which I haven't seen... which came out a month ago!).