Well done on getting your daughter away from that horrible bully op, you have done the right thing. And his psycho behaviour now he has lost his power over you just goes to show it.
But if you have evidince of abuse towards your child, please let the police know. Or make a point of discussing the bullying treatment with your solicitor so that they can say 'yes, she told me that was why she left' at divorce hearings ect... cover your bases.
It is likely he will threaten to try to take your kids (it's just an empty threat of course but you need to start preparing for him to have supervised access rights only, ideally). His sort always make that threat.
I would tell your daughter that daddy was mean to mummy and her and her brother (don't make it 'her fault) 'and so we left, because women should live in safe, happy homes and never put up with bullies'.
Dont worry too much about money, cms, jsa ect...should all add up and be plenty when you're staying with the parents. Plus you'll get something in the divorce likely.
He may have 40k...for now. But you have your freedom and your children's safety. And that is priceless.
I recommend learning about narcissists (npd) and narcissistic hoovering (the things they do to try get you to come back). As I think he will take this route. Melanie tonia Evan's is great on YouTube. She does a vid about 9 types of hoovering his sort might use.