Marley's Character Is A Human Plothole Machine

His existence in this movie, while needed to save Kevin in the end, really creates a lot of issues in this movie:

1) He's the only guy in the neighborhood who isnt away for Christmas, but is never mentioned by the Wet Bandits as being home. They never acknowledge his existence, they freely roam around the neighborhood robbing at will, never once worrying about him being home the whole time.

2) He's literally the McAllister's next door neighbor, and the only guy home for Christmas, and yet they never once bother to call him about Kevin. Instead, they keep calling the neighbor across the street, who they knew was going to Florida.

3) Despite regularly salting sidewalks at night, and just generally being around outside, Marley never notices the Wet Bandits robbing houses one after another.

4) Despite seeing Kevin all over town by himself, and clearly seeing nobody else is home next door, Marley never does anything about Kevin being home alone.

5) Even when Marley finally sees the Wet Bandits chasing Kevin, and eventually follows them across the street, and narrowly saves Kevins life by attacking the Wet Bandits, Marley just takes Kevin home and leaves him alone for yet another night! WTF!? Did he just drop the kid at the door and take off?

I understand why a character like Marley is in the movie, but man, his existence really does strain the credibility of the story. Its almost impossible for him to exist on that street and not have intervened at some point earlier in the movie.