I don't think either of them are "bad" people. Here's what I do take issue with: Life takes us to difficult places sometimes, whether alone or as part of a couple or other relationship. And if/when you love someone, part of what comes with the territory is giving somebody a safe space to talk about things they need to talk about even if/when they're not comfortable with talking about them. Sometimes that also means being a bit insistent about it, not for yourself, but for them. While it's possible that Angus had absolutely no clue what was going on with Faye, let's give the guy some credit and say that he's in tune with her enough to know if something's a bit off. When that happens, you can wait for someone to bring their problems up, or you can be a bit more proactive and let them know that it's important to you that they talk about it because THEY are important to you. And again, sometimes just letting someone know that you know something's wrong and are there to listen can help them open up to you where they might not have done so otherwise.
In a perfect world, we'd all be safe to say what we needed, when we needed, to whom we needed. In this imperfect world we're stuck with, sometimes it's up to us to be that still point to someone else so they have that safety where they may not have felt or known they had it before.
Agreed. I think it's fair to say that Angus has been a bit preoccupied with making his dream a reality, which is certainly understandable. Having said that, it means that he shares responsibility for these concerns not being brought to light and discussed, though Faye can be quite guarded when she wants to be, and I get the impression that she'd still find a way to brush them aside and avoid having the discussion. I think it's too easy to say Angus is a jerk - and again, anyone who doesn't particular care for him as a character is probably going to accept that explanation more readily - but it's something they haven't really handled properly as a couple.
Once again though, I think it makes them very relatable and realistically written. It's not that they're a bad couple, or not at all suited to one another. It just may be that it's not meant to be a lifelong relationship, because they do want different things. As I said, sometimes, that's just the way it goes.
In that respect, it's kind of like Marten and Dora's relationship in a way. It wasn't meant to last, some key issues got in the way, but it was probably good for both of them in the long run. It's not something they'd look back on and say "Well, that was a terrible period of my life." If Faye and Angus are through, I think they could say the same thing. I think it's been good for Faye in particular; as her therapist pointed out, her fling with Sven wasn't completely healthy, but also kind of a good step in getting over some of her issues. A healthier relationship that ultimately falls apart for far less caustic reasons is still another positive step forward for her.