ok having read the rest, in one small area I\ll play devil's advocate, from my own experience. Having lived in houses most of my life, I do find it hard to live in a small flat. You do what you have to, but it can be hard. Specially if the flat is in an area you don't feel safe in, as mine was.
at 35 I know that I could not easily live in a small flat with a partner and son. Maybe that's me being spoiled, but in truth it's hard when youre used to one thing to have to adjust to another that is physically perhaps not as nice. Please don't shoot me, mumsnet!
So it can be hard to adjust to less materially spacious surroundings, but the fact is that when you have to do it, you do. And finding yoruself a new parent comes under the heading of 'having to'. Also, won't it just be a for a short time? You will have your new house soon? He just has to put up with it for a short time.
I think it's essential that he is with you in the coming weeks. He does sound very nice overall, but you need to establish your independent life with him and not as part of his family´s clan.
Also, thinking about it I really do think he needs to know about that text. If it's a one off that's not so bad but something about it sounds a bit creepy. Possibly the "it's not a pretty sight" line combined with the lack of sense. At 41 weeks its hard to do anything!