Question: If Old Man Marley is actually a nice man (and not a "shovel slayer" as Buzz claims) then why does he always give Kevin that cold, creepy stare? After Kevin ran away the first time wouldn't he want to talk to Kevin the next time, to assure him that everything is okay?
Answer: Because he's understandably angry that Kevin's so unreasonably scared of him and assumes the worst in him without even getting a chance to know him. He never gets a chance to talk to him, because he always runs away too quickly. The first time he gives him that stare was when Kevin was watching him shovel from the window. Nobody would like to be stared at like that while doing a simple task.
Question: Maybe I missed it, but did the McAllisters even bother to call home? I don't remember them calling the house at all. Why wouldn't that be the first thing they do? Kevin seems to be pretty independent for his age. He might have not answered the door, but I'm sure he would have answered the phone.
Answer: They did but the power and phone lines were down due to a tree branch that had fallen on them the night before the family left. A flight attendant on their plane mentions that attempts had been made to call the McAllisters' home but "the phones are still out of order".
Question: Why does Kevin scream when he slaps the aftershave on his face? He didn't shave so he doesn't have any cuts, so it wouldn't burn at all.
Answer: Kevin did shave his face. His skin is sensitive from his first shave so the alcohol in the aftershave makes his face sting. Hence, the screaming.