As for Lilian and the Dower House, I think the thought of Justin buying, and therefore owning, it will be what makes her realise she doesn't love him enough to be marrying him. She loves that house and it's been her home for a long time.
I agree.
I also agree they should be buying it together, but going by Justin's comments sometime in the last week or so about she won't need her own money once they're married, I doubt he'd accept that. I think he likes to have full control where possible - and I also don't think he has any understanding of any reason why a woman might want or need some financial (and other) independence with him.
And the jealousy over Matt having owned the house and still being a trustee is pathetic. It's part of the control.
Though of course, deep down, all three of them know Lilian still has feelings for Matt, but Matt is the only one who recognises it. And of course he hasn't given up. So Justin has reason to be insecure, but it's still pathetic, and if I were Lilian, it would do the exact opposite of endearing him to me in any way. I hope she was listening to the question she asked about if he still loved her, rather than his answer.