I agree with you somewhat. Hence why I said ignore the door when he knocks. If there's cctv up, if he tries anything it will be recorded. Sometimes you have to stand up for yourself and not live in fear in your own home of upsetting a potential nutter.
In that instance, if that's correct, everything will annoy him anyway. He will already be annoyed and see himself as the victim if the OP has asked him to move his car, and remove his stuff.
What do you suggest she does then? Just puts up with it? Genuine question.
Get evidence and play by the rules herself. I have someone who lives next door who is like this, tries to be your best friend takes the piss over and over and when you call a halt starts a vendetta against you. if I were to play them at their own game then they would have evidence of my wrongdoings. as it is, they complain and complain and complain about me to various organisations, housing, council, noise abatement police etc but nothing comes of it because there is no evidence from them about me, but plenty from me about them and I'm not the one who complains ( I have never instigated a complaint, I just give my evidence to those who write or visit me ) Now for the last half year, they have been deadly quiet and I think it's because they have been told by housing they are on thin ice now.
I was also married to a person like this and you never win, in their head, everything you do is done to annoy them on purpose, even breathing. they take and take and then act like your giving is their right. That is why you have to be cleverer than they are. my ex was very violent as well. Next door is also aggressive when they don't get their way but over-the-top friendly when she does. Only the OP knows what way she thinks her neighbour will be and can act accordingly.
Just gives me uneasy vibes when he is already making life harder just because she isn't as "giving" as she was.