Okay, the discussion went into another direction than intended, but I'll happily go with the flow.
NightBird & cryptwarmer(love you username btw, sounds naughty)
If Buffy started ensouling people (why has that never been attempted?) I think she would discover that a lot of them would choose to be "evil"(that's a very loose term but I'll use it) and few not. After all, a lot of humans are jerks without the thirst for blood working it's way.
But some of them, like Angel & Spike, are different.
I actually compare being sired as the process of being drugged against your will. Imagined that you're drugged, and that you do a lot of horrible things, then the drugs wear of and you remember everything. Then you're not to blame. For example, if you force a lot of alcohol into someone and they become agressive and rape someone, that's not their fault. The blame belongs with the person that drugged you (your sire). However if the drug-person(your sire) has been drugged by someone else (your grand-sire) they're not to blame either.
But you should feel horrible, because that shows you're human and got empathy, but it's not your fault. However, if you continue being evil after "the drugs wearing of", then the sould might neevr have mattered. Although the added demoness is something that's not their fault of course, but apparently something some people (Angel & Spike) could overcome, even tough they're not still humans.
So a soul could be very important to a persons personlity. Or as I think in Warren's case, it means shit.
And a lot of demons are nice, even tough they clearly lack a human soul(not sure what they have), like Lorne, kinda Clem(he did hang out with Spike, a serial killer, so I don't know...)
And cryptwarmer, after reading your post about Xander's hypocrisy, I felt that I LOVE YOU 😉
Because it's so true. I have no idea how Anya's soul changed between being demon or not, (but I believe that she actually kept her soul during her demon-days) I just know that Xander hate towards demons who have done wrong in the past (Angel, Spike) were nowhere to be seen when he got together with Anya. What a load of horseshit. I get it, she's a girl now and a human, she's all harmless, but come on. Hypocrite.
I also agree to what you're saying about Xander getting over the rape too quickly to be realistic, but then again, I really need to re-watch season 7. But one scene with hate and loathing about the rape-attempt would be nice, not just the general eww-he's-a-vamp-and-has-to-sleep-in-the-closet-attitude.
Girl With Soul
I'm not sure if Buffy forgave Spike for the rape-attempt that quickly, just that she was desperate and thought that the rape-attempt was a misstake from his side so she took the chance to hide Dawn with him. I really wish the writers would have taken more time to explain/explore Buffy's feelings on the subject. Almost being raped is a big thing after all.
On the whole "Buffy just denied that Spike could love her without soul because that would mean Angel could have but didn't."I'm even less sure.
I have never seen it that way, but yeah, having compared Angel to Angelus must have made her relationship with Spike even more painful. She might have wondered why not Angel's love survived. Thank you for that insight. I however think that the fact that Spike was a sadistic mass-murderer was the main reason Buffy had a hard time getting used to thinking that Spike might have romantic feelings. I mean come on, we all like to think that the bad guys wear black hats and are not nice in any way, so that we don't have to feel sorry for them. That makes things easier. We don't want to find out that serial-rapists/murderer/bullies read the same books we do, admire the same people or God good, could like us.
If a mass-murderer started liking me, I would go to a therapist to try to find out what the hells wrong with me. Kinda what Buffy did with Tara.