In regards to other possibilities available to them to try and work things out, what do you think they could have tried? pure curiousity here, not being smart🙂 and what you said about the manner in which he broke up her being cruel. I agree and disagree with it. I disagree because I don't there was any other way Buffy would have accepted what he was saying but I agree that it had a awful affect on her. I sometimes think it was worse for her in someways than losing him to Angelus and sending him to hell because he was choosing to leave her, while the whole Angelus ordeal he wasn't in control.
Things they could have done? Well, the main problem seemed to be that being with Buffy made Angel too happy. It wasn't the sex, exactly, that made Angel perfectly happy. We've seen him have perfectly good sex with other people. I'm trying not to be crude here, but I don't think it's the actual act of intercourse or even the sensation of orgasm that make Angel so happy that he loses his soul. I think it's what that means when he's with Buffy. For them, the vampire and the slayer, sex is the breaking down of all of the barriers that keep them apart. Chastity was the solution that they found not because Angel's some weird sex addict or something, but because as long as there was something between them, some part of happiness that they could never really have, then they would never be perfectly happy. The act of denying themselves a certain degree of intimacy made them less-than-perfectly happy. If they followed their hormones and gave into those impulses, though, then death would follow. Why? Not because of the sex itself, but because of the knowledge that there was nothing between them. At least, that's my understanding of their main problem as a couple.
The solution to that problem, then, seems to be to make sure there is always something between them. It doesn't necessarily have to be sex. They could have tried the long-distance thing. Believe me, that's no walk in the park. My husband and I did the long-distance thing for three years before we got married. They could have had a secret affair in which Angel could never be part of Buffy's family/friendly gatherings. No scooby meetings. No birthday parties. No Thanksgiving dinner. You get the idea. They could have tried sleeping with other people (casual sex, like with Parker) so that they could never really "belong" to one another exclusively. In many ways, this aspect of their story seemed very much like the story of a couple faced with sexual dysfunction or with the danger of passing on an STD. That being the case, they could even have stuck out their self-imposed semi-celibacy just as real life couples do when faced with this issue.
Truthfully, I think it entirely possible that the way things went last time would be enough to render any future sexual encounters tainted by that memory to the extent that they would never be "perfectly" happy again. Knowing that the possibility is there seems like it would make sex a lot scarier from then on out.
These are all things they could have tried -- or at least discussed. I'm sure there are more, too, but this is getting sort of long-winded. No solution is perfect, I'll grant you. And maybe the bulk of discussion should have happened off-screen since it's not exactly riveting dialogue, but it is a mature and frank discussion of their options, at least. It wasn't like Angel thought. It wasn't like they were either together and the world was doomed or apart and miserable. There were plenty of less-than-perfectly-appealing alternatives in the middle. I think he owed her a consideration of these options and a say in the status of their relationship, at least.