How to Fix This Movie.
I know I'm 14 years too late, but I don't care. Here is how Home Alone 4 could've been salvaged:
1. And this would've been EASY: change the characters' names. There is NO way you're going to make people believe that the characters seen in this movie are the same as in the first two films. Not even first-time viewers are going to believe that. Therefore, just make them new characters. Call Kevin "Jimmy", have their last name me 'McDonnell' or something. And as for "Marv" (LOL), make him a completely new criminal named Vic. Say how he did time with Harry Marv, how he looked up to them, until he heard they were outsmarted by a kid...twice.
2. Keep the stuff with the smart house, the bitchy girlfriend, the royal family, and especially Prescott and the twist as those were the best parts. Just elaborate a little more on each, especially the royal family. They're only mentioned as an afterthought.
3. Less crotch-shots. Be more creative with traps.
And there you go. Sure, the movie would still be lame, but at least it wouldn't be INSULTING.