Malibu is a great city with spectacular scenery and kind of an unusual vibe. It is somewhat family friendly and there are lots of activities and groups in the area. Do a search on Mailibu and Family, also look at meetup groups etc. The only downside is PCH can get really busy from time to time, mostly on the southern end, but you can always take Topanga or Las Virgines Rd to the 101 and have access to Calabasas/Agoura/Westlake/Thousand Oaks area - all of which are great family communities.
Santa Monica is a bit less family friendly from what we have seen, it is very very cliquish, though there are always some really nice people, crime is a bit higher and it is as expensive as Malibu but without the incredible views.
Laguna Beach is similar to Malibu in many ways, coastal community, protected from other urbanization. Lower crime than anywhere in LA county. Busy on weekends, but a beautiful community to live in - Newport Coast is also another outstanding community with lots of family friendly events. I have found Newport Coast to be much more family friendly than Laguna Beach, but that may be personal experience.
Hope this helps
