Also, google this judge assigned to your case. Sometimes people make comments about which lawyers that particular judge favors. Ask around. Try and find out if there is a particular lawyer that always wins in this judge's courts. That would be the lawyer I would hire.
Secondly, IMO, it would help you to have someone there with you as a witness. I would hire someone who has experience testifying in court. A lawyer, an off duty policeman (this would serve two purposes, it would get the police department to understand your situation and maybe begin to see your side of things through this one off duty policeman's accounts), a court appointed child advocate. Any of these people would serve as good people to have around when your A is picking up/dropping off girls or staying over night.
Also try and have the judge appoint someone in addition to the therapist to be the girl's advocate. This is usually a lawyer, who acts as the children's lawyer. Their only goal and job is to ensure your daughter's well fares and best interests are being met. That way it isn't your word or his.
I went through and am still going through thing with my XH (not an A) so I understand and sympathize with you. Please try and listen to what the people in here are telling you. I know it is blunt and comes across as harsh. But their hearts are in the right place and they are trying to help you. You are not going to win this verbal battle with him. No one will win and the girls witnessing this are the true losers. It doesn't matter who is right at this point, try not to engage. Also, I did find with my XH that as soon as I started cooperating with him and giving him everything he "wanted" he no longer wanted it. He tried to force all three of my children to have visitation even after he had abused my daughters. I spent years fighting it and trying to protect my girls. When I couldn't fight it any longer all three wet for visitation. That was the last time he forced it. He didn't want all three children. He just wanted me to suffer. And as soon as he thought it wasn't making me miserable, he no longer wanted it.
I like the idea of the security cameras inside an outside your home. Even if it is not admirable in court, the fact that he knows he is being recorded will force him to behave differently.
I wish you much luck with everything and hope for your safety.
One last thought, look to see if there is an age in your state where your girls get to choose whether they see their dad or not.