Question: In the first movie, Kevin's mom says there are 15 people in the house. In the 2nd movie, the two moms count 7 each which is 14. Who was removed in the 2nd movie?
Question: Harry opens a door causing a bag of tools to fall on his head. In real life, wouldn't Harry have been badly injured if that really did happen to him?
Answer: The YouTube channel Screen Junkies did a video consulting with a doctor called "Honest Action - Home Alone" in which they break down all the traps Harry and Marv encounter and what the real consequences would have been. For this one in particular, they said Harry would have been killed by a skull fracture and a possible epidural hematoma.
Answer: There are numerous YouTube videos of real doctors analyzing the traps in Home Alone 1&2 and what would "really" happen to Harry and Marv and almost every doctor who examined the bag of wrenches trap said Harry would've most likely died of severe head trauma, brain bleeding, skull fracture etc. You gotta check them out.
Answer: Yes it would have. In real life, a lot of the traps Kevin sets in both films would have seriously injured or killed both Harry and Marv.
Question: Why can't Kevin just call the police that Harry and Marv is about to rob Duncan's toy chest at midnight instead of stopping them himself?
Answer: There is no reason other than it would be an incredibly boring movie if he did that. Obviously that's what one would do in real life, but if one buys that Marv and Harry can survive the multiple fatal traps they encounter, then one can suspend disbelief enough to accept a questionable decision to advance the plot.
Answer: I think it's the same reason he didn't call the cops in the first film, he was afraid of the cops because he committed a crime himself. While it could be considered a stretch, it's not really explained in the films. In the first film he is chased by the cop for stealing a toothbrush and in the second film the hotel has found out Kevin was using a stolen credit card, so he flees. Of course, he ends up calling the cops in the first film and makes a recording of their confession for the cops in the second film.
Answer: What cop would believe a little boy that he knows that two escaped convicts, he single handedly captured before, we're going to rob a store.
Police are required to follow up on reports. They can't just disregard a report because they think it's unlikely.
Answer: Heather McCallister wasn't in Home Alone 2. She's the daughter of Rob McCallister whom everyone was visiting in Paris. Heather was in college in the US and tagged along with everyone. When everyone is going to Miami, Rob's family is still in Paris (Heather is either with them in Paris or still at school).