Hard, a lot of the things you are saying resonate with me. My ex was remarkably similar. And you know what? The court saw through him. He went for residency and ended up without even contact.
What swung it for me was the first judge at the initial hearings insisted on psychiatric reports (they had to do them on me and my husband, to get the ex to agree). He delayed the whole process, maybe adding a year to it, refusing to see the court appointed psych, but went in the end and they said he was one of the worst cases of paranoid personality disorder they had ever seen. And his MO was remarkably like your ex's.
He'd record things (even phone conversations); make a nuisance of himself with the boys' nursery; do weird things like say the kids didn't need to wear nappies as no-one bothered in the streets of Naples (he was half Italian) then when the baby shat on the floor, he'd point to it as my neglect (mysteriously the nappy free baby was only allowed in my house on my brand new carpets not his tatty flat). Once, he took my son for a 'walk round the pond' opposite my house, and the kid came back with all his hair shaved off. "To look like daddy". He'd let him eat a permanent diet of cakes and sweets - did so much damage that a year or two on, my son had to have extractions and fillings on his baby teeth (none of my older kids, and my younger son never had to have as I had taken care of them). Since he hasn't seen his birth dad he has had one filling in ten years...
The thing that really rang bells though was when you said about him letting her stay up til all hours. My ex did that too. He said my strict bedtimes were 'cruel' and the same claptrap about loving the boys and wanting to spend every second with them... But then, when a random woman at nursery told him her kid's bedtime was 7 o'clock, suddenly that was gospel and they were to bed at 7 because this guru of child-rearing (some yuppy with her first baby - I had 5 kids!) told him so.
When we split I still drive the 200 miles to London to take the boys to stay with him (with me there - they were very young) for weekends, etc. One trick he'd play was he'd "Just take son outside to 'play' in your car" - the play always involved my son turning on all the lights, etc which he'd ;forget' to turn off. Resulting in flat battery. Pissed him off that I just rang the RAC to get me started. All blatant attempts to make me not take the kids home. He did that more than once.
Seriously, your ex is mentally ill. Mine was so far gone he was unable to con another woman, and remains alone but the fact your's has remained credible enough to go on to have a second family, doesn't change the fact he is probably badly mentally ill.
Make sure the Family Courts run a psych evaluation on him. It may go in your favour. The psychiatrist in our case told the courts my husband and I were totally normal, and he was so badly mentally ill, it would be damaging for kids to be around him. All those manipulative behaviours were tried by him and the courts saw through it all.
I used to wonder why the only thing he ever did for our oldest was take him to a mtoher and baby group once a week. Of course, when it went to court there were the yuppy mothers writing testimonials to what a fantastic daddy he was, and how I was so indifferent I didn't even bother to go. He had set me up all along. Those 2 hours a week were when I was heavily pregnant and exhausted and I thought he was being 'kind'.
The judge saw through the 'evidence' he amassed - inf act recording conversations etc made him look even more paranoid and mentally ill.
You might be surprised how used the system is to idiots like this.