If you are unmarried (to the dad) then you do not have to have him on the birth certificate,you can't have him on it unless he either attends to register with you or signs the declaration and it gets handed to the registrar. If he is not named on the birth certificate this means he does not have parental responsibility.
PR means he has certain rights to do things (exactly the same legal rights that you obtain at birth and he would if you are legally married) to obtain PR without being named as the dad on the birth cert he needs either your consent via a PR agreement OR a court order. Without PR he effectively is not the father for any thing other than CSA.
You do not have to do anything,no chasing no trying to involve him no nothing. The onus is on him to attempt to assert or obtain any rights or responsibilities.
With all due respect pregnant women tend not to randomly break up with the father of their unborn child without very good reason,your talking about someone who chats about child abuse as if it is acceptable and normal as well as something to be expected. I'm guessing that he has other behaviour issues or you have concerns about him.
If I'm right and if I was in your shoes I would do absolutely nothing nothing at all, I wouldn't go out of my way to involve him with the pregnancy and I wouldn't inform him of the birth.
If he directly asked I would not lie but I would not offer any info.i would wait and see what move he makes if any.
Legal aid is a no go as unless you have a provable history of domestic abuse or its a ss cp case you cannot get it for family law cases any more that means he also can't get it.
If he does attempt court action then comes the time that you need legal advice and a action plan but its more likely he won't bother.if he does that is the time when you can take steps to make sure his parents are not able to harm your child.