How Do I Protect My Children?
The most frequent source of harm to children during a divorce or parenting dispute is conflict. It is the stress, pressure and pain children experience from fighting parents, especially when parents include children in the conflict. For example, parents often believe it is the 'right thing to do' to 'tell the children the truth.' While I am not exactly advising deception, telling children 'the truth' is most frequently a guise to simply complain about the other parent, to try to get the child to 'side' with one parent, to unburden oneself, etc. So, one way to protect children is to leave them out of your relationship with the other parent.
If you have legitimate safety concerns about the other parent towards your children, it is about documentation. Identify your concerns very specifically. Relate those concerns to specific harm you feel may be a consequence of those concerns. Keep a journal.