I am so sorry to hear how things reached the point they did. Your "friend" is a piece of work. Unreal. I am so sorry.
As for his fb posts. I'd print out a page showing some of them to save to show a lawyer (or use to keep up the RO after a month- if it expires after 30 days like ours do) bc that last one about paying back time with interest sounds a bit threatening to me. Maybe I'm reading into everything right now a bit too much but I'd rather be safe than sorry...
Sending you lots of warm thoughts and hugs from a far.