In the shownote Which takes place before the movie, as Flint and Sam are high-schoolers and Calvin is an infant, there's an episode detailing how Sam and Flint met in high school, in which they begin competing in who can create better devices. By the end, Sam confesses that she's scared to try and make friends because she'll most likely end up moving out of Swallow Falls in the future, to which Flint offers to wipe both of their memories of each other when that time comes, thereby turning a Retcon into a Relationship Reset Button!
Brent tossing away his diaper is symbolic of him liberating himself of his former image...and then you realize he's naked inside a giant chicken. Think about it from the chicken's point of view: It eats something (Brent) which then begins wearing it as a suit, controlling its every action — and it's presumably still alive and conscious, but helpless, from that point forward... A fate worse than death indeed!
The Spray On Shoes, when you really think about them. Since they have the capability to stop the entire machine, which when you think about it, must be pushing billions of pounds of pressure, and eventually cause it to EXPLODE, coupled with the fact that they NEVER COME OFF, they are the deadliest weapon in the universe. Think about what could happen if someone sprayed them on your face or your eyes. You'd suffocate due to the mouth and windpipe being obstructed and you being unable to breathe, which then would cause instant brain-death. Long story short, you are pretty much fucked. SWEET DREAMS.
Let's just hope that Chewandswallow doesn't have any greedy politicians around who might want to take advantage of this. Oh Wait!...
That's possibly lampshaded when Flint takes the bottle of Spray On Shoes from Steve, saying "Don't spray that in your mouth."
Sure, raining ice cream may be heaven for some, but what of the lactose-intolerant? And giant shrimp? Probably quite dangerous to those with seafood allergies, especially if they grow large enough to wreck a house or car. Sam says she's deathly allergic to peanuts—regular-sized ones could kill her. Imagine what a giant peanut would do to somebody similarly-afflicted....
When you stop to think about it, it's actually really fortunate that Brent tackled Sam and Flint on their way to the machine, since, as Sam says, the path they were taking would be "a straight shot". Given where they were, it was probably the intake pipe. Which leads to a machine that converts water into food. Human beings are mostly water... so, what would have happened if they fell in? Nothinggood,that's for sure.