Kind of surprised at some of the flak Angus is copping here. Granted, he has his faults like everyone else, and he's being a bit insensitive here, but I think the way Faye has handled the situation to date does play a significant role in that.
She's been outwardly supportive and enthusiastic, while keeping all her concerns and disappointment with the situation to herself. You could say that it's because she loves Angus and didn't want to bring him down, and I'd agree that's definitely part of it. However, I think it's also quite likely that she just didn't want to confront a challenging issue in their relationship, or have a difficult conversation.
From Angus' perspective, she's been cheering him on as he's pursued a dream job, a dream job that he told Faye about on their first proper date. He goes to New York, he gets the job, and wants to share his excitement and happiness with his significant other upon his return. However, now she's letting her true feelings out and kind of raining on his parade; she has a point, of course, but because Faye never brought this stuff up before, Angus is understandably taken aback.
I guess if you don't particularly like Angus, then this development lends itself well to demonising him to some extent, and seeing him as a self-centred jerk who only cares about himself, the "chase", and whatnot. And to be fair, he does have some jerkish tendencies, so that's not completely off the mark. I can definitely see where you're coming from.
Still, I think Faye shares some responsibility here, because she wanted to avoid a painful discussion and a tough situation. She and Dora have made fun of Marten's complacency and passiveness in the past, but I think this whole arc shows that Faye's still in need of some development/growing up, and that she's just as complacent as Marten. Sure, she's come a long way, admirably so given her "hella issues", but she's still trying to ignore her problems and avoid dealing with unpleasant situations if possible. She's also pretty content with the status quo, which you could argue is actually worse than Marten's moping. He at least knows he should be doing something more, even if he doesn't know what. Faye seems content not to reach any higher.
I'd agree that the writing has been on the wall since the audition first came up. I think both characters could've handled the situation better, but neither are the "bad guy" here, and I can understand where they're both coming from. A break-up seems inevitable, and if that is the case, I think Jeph has written it quite well, in a way that's very realistic. Sometimes, these things happens. You love the other person, the relationship works, but as you each move forward with your lives and pursue new goals, you may grow apart or you may be unwilling to make sacrifices, or make the best of a tough situation. Seems that's what we're seeing here.