"I'm trying to work out if it's a threat or not." I'd ask him what he means by that. Make him put it in writing, hopefully shoot himself in the foot! But yes I'd take it as a threat. He's panicking cos he knows he's losing his control of you.
If he means court, great! Bring it on!
If you can provide evidence of abuse you might be able to get legal aid. If you can't you can still self represent and there's other options of charitable support there even.
Heard good things on here about these people
www.ncdv.org.uk
Also remember taking you to court is cost and hassle for him too, I doubt very much he actually wants to do that. My ex took me to court cost him £10,000's and in the end he got awarded LESS contact than I was offering and which he wasn't making use of anyway!
"Before court there is mediation (you can insist on shuttle mediation) - court is a long way off!!!!" This too. When my ex took me to court it was before this was the procedure. Mediation will also cost him money so again he's not really gonna want to do that.
"Nope he's not paying anything yet." He should be but this is further proof he doesn't WANT to shell out ANY money wrt this situation.
Get onto cms ASAP and get a claim in.
"That he's not paying CMS is abominable, and he won't want the court finding out that" it is abominable, however as maintenance and contact are legally separated you're not even allowed to mention it in court.
But as pp rightly say that's a LONG way off anyway, even back when you weren't required to try/consider meditation first it took months to even get initial date let alone anything else. This guy hasn't the stamina for that I'm betting.
He's in your head and he's got you convinced he has some kind of super powers - he hasn't! He's just a pathetic bully lashing out because he's losing control of his victim.