Oh my WHIG,
I am so sorry you had to go through all that. Sorry that happened with his toe. My first thought was that he wanted you to do just that-so he could get hurt, and blame you.
I can relate on the deal making...the never, ever anymore again types of rules.
I thought I was the only adult who had to listen to these kinds of *rules* and ultimatums from my UBPDH. Like he's the Emperor of the world.
It's bizarre isn't it how they insist on THEIR way or no way.
Mine will stand there and say firmly "OK HERE"S THE DEAL..." Or he will actually say NEW RULE! and then proceed to announce the new deal/rule and how it will affect him, or me, or US.
As though life and r/s are GAMES in which he and only HE gets to call the shots.
I have never ever heard anything like it!
Then he proceeds to break his own rules, or deals.
I never know how to react to this stuff. The rules, demands, conditions...
Sometimes I laugh, before I catch myself and then I tell him WE are NOT playing Monopoly!
Sometimes that will shut the behavior off when he realizes how absurd he sounds.
Other times he gets mad.
I would address the threats towards your son. That's NOT OK. No matter how upset or hurt he is. My H has also said "F your kids" (mine are all grown and dislike H , heartily) I just ignore that. He knows they deeply dislike him. I have told him that I did tell my kids about his shtty behavior. I will not suffer alone in silence! So there's not much affection either way...I always feel like I have to choose between them and H...esp. when there are family events.
BUT the actual threat on your son is a big

. I would call him on that. It's no joke.
I know that PwBPD say lots of hurtful ugly things-but towards a young person it's UN-acceptable.
that's where the disorder looks really scary.
I am so sorry that you have to deal with this.
GL