Ahhhhhhhh it's one of those things where I can't say exactly until I know exactly how it goes down. I know he'll be pretty heartbroken, though I'm not sure how much he'll actually show or voice it. The thing about Matthias is that he's such a romantic at heart, and his upbringing view of relationships is SO traditional, that by now he would have already asked Dutch to marry him, would already be talking about kids, etc - but she's never said she loves him, and wouldn't move in with him when he asked, so he's basically following her lead. He can't really understand why not, though, because she's with him (and partly wonders 'what's wrong with me?'), but he doesn't try to pressure her because he loves her so much he's just grateful to be with her in whatever capacity she'll allow, and wants her to be happy.

So for him to be involved with two people who want to keep him at arms length is tough for him. I think he'll be hurt, I think if Marcus tells him why then he'll try to argue that he doesn't need to be protected because he can protect himself, but ultimately he'll give Marcus what he wants because he wants Marcus to be happy.

...I just got super tired, so I'm going to answer the other two tomorrow!