Crikey, sounds like you've been through more than I have. Had the same with my ex though - used to beat the cr@p out of the kids and me, then went to court when I stopped overnight stays because he was beating seven bells out of them. And because his parents were well off, he got a good solicitor, and tried to claim in court it was ME who was beating the kids up! Imagine if a court had believed him and sent the kids back to him for more beatings? I also apparently killed cats in my spare time, and even though I am 5ft 1 and he is 6ft 1, apparently I was always punching him in the face in front of the kids. He must have stood there waiting until I brought a chair to stand on to hit him then....
Thankfully, after going through CAFCASS (in our case twice, through two court hearings over two years), we finally got the result we wanted. CAFCASS talk to the kids if they are old enough and get their spin on things. First CAFCASS officer had made his mind up before he even met me and the kids and we got shafted badly. Second one listened to everything the kids said and we got the best result for the kids i.e supervised contact only. Which will explode this week because the youngest wants to miss one contact session a fortnight to attend lessons on learning to play drums (yes, she is a tomboy). Probably means me getting dragged back to court again, but what is learning drums compared to sitting bored in McDs?
Anyway, as usual, I ramble. Basically, in a court case, CAFCASS will get involved. They will take note of if there is any regular contact, if the ex attends regularly for contact, if contact is constructive, if he supports the child financially and emotionally. They will check if the child is of school age whether he takes care of things like helping with homework, fetching and carrying to afterschool clubs etc. They take into account what happens when the ex does have contact with the child, is it beneficial, and whether the resident parent is dealing with the situation in a mature, sensible and conciliatory way. If the child is willing, able and old enough to explain their feelings, it will be made note of.
If, in the worst case scenario, CAFCASS make a decision for more contact, then any decent reason to stop contact or restrict it will result in it being brought back to court again. But bear in mind, stopping contact means breaking a court order and can result in imprisonment for the resident parent even if the absent parent has been abusing or neglecting the child/ren. But it would result in a review, and by that time the child gets older so what they say to CAFCASS, their own feelings, lend more weight as time goes on.
Hope your daughter gets through it okay, Frank. I know it was an unbelievable hell for me going through court, because it gets nasty, and some people aren't beyond lying and dirty tricks. I'm sure with a strong family backing her, and if it does go to CAFCASS, insist that you are interviewed in conjunction with preparation of the final report and your opinions noted in that it would cause more disruption and harm than it would good for your grandchild. In my case, CAFCASS spoke to my ex's family, but didn't bother speaking to mine, so it made it look as though he had loads of support and I had none, which didn't help the kids and my case any.