Seek legal advice regarding the house purplejay, do not assume he will automatically get a good share of it. I had all the paperwork to prove I had put all the equity into our matrimonial home initially from the sale of my lone owned flat, I also had proof of the remainder my parents contributed to help us buy in a better area (thankfully had legal documents drawn up at he time). I also had prove he had only contributed debt when we got together. All of this meant I ended up getting pretty much all of or house, he got 10k one off payment which I just stuck on my mortgage. Once divorced I sold my house and downsized a tiny bit but in a better area and that covered clearing myself of the extra 10k.
I never thought about where he might live or how. He was on benefits by then and tbh I had to stop looking after him. He had no choice so did stand on his two feet (moved in and out of the woman's he had the affair with and a bedsit when they argued). Think you need to do the same unfortunately, he's not your responsibility and probably the only way he will sort himself out is if you take his comfort blanket away.
Are we friends? No, he is a total idiot and pond life. Do we tolerate each other? Yes, we communicate nicely face to face for J. If we argue it is via short texts, rare now though after 6 or 7 years (stopped counting or caring). Do stuff together? No, not now. I guess if / when J graduates or marries we will have to get along for the day, strangely I can rub along with his wife, the woman he cheated on me with better (possibly because I pity her)!
Other ex boyfriends, 2 from late teens /early 20's I'm Facebook friends with and chat with. One is local and a family friend so we bump into each and make comfortable small talk but that's it. The other lives abroad, has a young family, he asks for parenting tips given my job and once asked why it didn't work out with us, eek! Moved on from that now though and just chat online occasionally.