These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Crowning Moment of Funny: In the sequel, Tom comes to his son's aid when he's harassed by some jerkass teenagers by speaking fluent Jive Turkey at them and leaving them dumbfounded.
Designated Villain/ Informed Wrongness: Nora's boyfriend. He isn't fond of children, and appears to be quite awkward around them. This of course makes him a bad person, and we're supposed to find it funny when the kids play pranks on him that could seriously hurt him (setting him on fire, making him trip face first into a paddling pool, etc). Even the parents don't seem to treat it as seriously as they should, it's no wonder he's not fond of the kids if they act like little brats to him.
He isn't treated as a bad guy for that by the parents of his fiance, they both are mad at the kids for it. She only leaves him when he refuses to go look for Mark, who at that point in the film had ran away, just to watch his own commerical. Even with the way the kids treated him that's still wrong not to go look for your girlfriend's younger brother.
Tearjerker: The father's death in the first novel and the treatment of Mark in the new film.
Values Dissonance: When the mother leaves the children with their father for the duration of a short work-related trip, everything goes to hell due to the father's inability to take care of his family. The ending has her realize her mistake and promise never to leave the children again. This is a bit jarring to viewers from cultures where women are expected to work and fathers are expected to participate in childcare. (It's also the exact opposite of the original book, where much of the entertainment value came from the father's many unique and amazing methods of organizing the family's life to make it run smoother. Which worked. Of course, him being a workplace management researcher and everything.)