How long should I wait? (long question, just skip if you'd not like to read it :) )?

IMMEDIATELY. This guy should be in JAIL! Why the courts aren't siding with you is puzzling. Usually they always side with the mother unless the mother is unfit (mental illness, untreated drug addiction). Whatever the case, they need to be as far away from your ex as possible. This guy is nothing but an abusive piece of trash, and keeping your kids around him will have profound effects on them.