Ask a landlord-tenant lawyer and get answers ASAP
No matter the cause of your eviction, there is no self-remedy to eviction actions in California. So, the Landlord cannot change your locks and force you out without a Court Order if you refuse to leave. The Landlord MUST use the Court system to accomplish the eviction. Otherwise, the eviction is unlawful and you can file for damages.
You can also file complaint against the Landlord with your Attorney General's Office:
As for the Landlord's vandalizing your property and other threats, you need to go to your local Courthouse and apply for a Civil Harassment Order. Click on the link below for more information:
Finally, you need to report the Landlord immediately to the Police for his suspicious behavior around where the children walk.