When Ned Beatty is talking with the kids, as him and Liev Schrieber are painting the fence, that is absolute magic. These two non-actor kids getting to share the screen with a legend, and Beatty is just eating it up.
Everything bad about the first film is amplified here. What certainly isn't helping is all of the sequel cliches that permeate the film. Romantic turmoil in the lead couples, expanding to international locales, introducing the mother, retconning of the main character's backstory, etc. The Ed Harris villain is pointless, and flip flops so many times, that it is frustrating to watch.
Things I would do differently.
1. Remove the food from the freezer where they put the bodies.
2. Build the wall out of something stronger than cardboard.
3. Close and seriously board up the doors behind the built wall.
4. Seduce Francine away from Flyboy.
5. Take all the guns out of the gun store.
6. Never take off the fur coat.
7. Eat a whole ton of cheese.