It hinder her in all aspects in the long run.
I don't think Giles leaving at such a crucial time help either as I feel perhaps if he had been around for much longer, he would have notice the effects of what Buffy was going through with her return and help her in a more productive and healthy way for her to heal.
Obviously her friends were going through their own stuff however I think if Giles got to understand the depths of Buffy's trauma, he would have gather the rest of the Scoobies up and have a good talking to them about needing to be there for Buffy.
Spike's involvement prolonged her pain and torment because he just wasn't equipped to help her in a selfless way. The situation that came about was to his advantage particularly as he could see the growing gap between Buffy and her love ones especially when she spoke openly and admitted what she felt happened to her when she died.
As a soulless vampire, his own wants will be why he will do the things he does. Understanding Buffy has darkness in her doesn't mean she needs to be drawn more to that side of herself. She can be aware of it and acknowledge it's a part of her but know she is much more than that. But Spike is not concerned about Buffy for those reasons. He wants her whatever the cost to her own self worth because his views of love as a soulless creature are unhealthy and toxic.
I know some think it's unfair when talking about Spike in this situation and then the comparison with Angel from certain people.
My thoughts are that because spuffy started from such where it did in Spike being 'in love' with Buffy without a soul, it makes it a bit more complex and complicated especially because many were championing for them to be a pair before the end of this series and not with the knowledge of Spike going to get a/his soul for her.
There were many who were happy with their 'relationship' even though it was extremely messy and toxic however their continuous 'shagging' was met with joy particularly as it was one up on what she had with Angel. (Which I remember from a few websites and magazines back in the day). But then along came Seeing Red and many people only then felt that the relationship (at that time) was destroyed. Because it would seem nothing before that could be question as not being good for Buffy in the first place.
The main thing for me when Angel lost his soul was that as hard as it was seeing that soulless side of him, it would never enter my mind for wanting Buffy to even think of completing being in any kind of romantic/sexual relationship with Angel/us. Even with all the problematic opinions of their relationship as it is viewed today and also the limitations of what they had to go through due to Angel's soul, the romantic relationship works for me because it just about Buffy and Angel's connection (which was complicated enough) and nothing to do with anything regarding how Angelus felt about Buffy (which was not a lot apart from hatred).
I just believe that for many they were rooting for spuffy to happen even before the soul storyline and if they hadn't created Spike being resouled, it still wouldn't have made a difference to those that wanted them together in the first place as Spike had the chip in his brain to neuter him from harming any humans
Spike getting back a soul was them trying to give the story and character more layers which I can understand was appealing for many and would help to soften the backlash of what Seeing Red had caused but it didn't work for me.
Many years have passed and while I can appreciate all efforts that was given by everyone in the last two series/seasons of BTVS, I know they will always be the ones I least enjoy and watch.
I think regardless of Buffy's actions in s5 and her treatment of Spike at the latter half of that series, there were plenty of reasons for why she was that way with him especially with her main and top priority in keeping Dawn safe and understanding and using Spike for her own benefits. There was a sense of gratitude for his help but knowing it was only because of his feelings for her and not just because it was for the greater good. I absolutely believe this version of Buffy if she had never sacrifice herself and somehow defeated Glory and save Dawn and the world would have not had any kind of relationship with Spike moving forward from that battle. The powers that be and the writers deliberately had to come up with a way that would justify Buffy entering a relationship with a soulless being in Spike and being completely depress and detach having been pulled away from heaven was the only way to go.
Sorry for the rambling!