No, they didn't. The comic plotlines don't feature this particular event. It might just be a misunderstanding or a rumor.
No, they didn't. Their relationship had its ups and downs but didn't end up in a traditional togetherness.
It varies from comic to comic. Sometimes they have a romantic connection, while in others, their relationship is more complicated or not existent at all.
The status of Spike and Buffy's relationship in the comics varies. Sometimes they are shown as a couple, while in other instances, their relationship is more complicated or undefined. It all comes down to the particular comic series and its plot.
In the comics, Wanda and Pietro did not sleep together. Their relationship was more focused on their superhero activities and family dynamics rather than anything of that nature.
Buffy would probably be involved. Since she's the slayer and Xander is her friend, she'd be on a mission to rescue him from Spike. Willow could also be in it. As Xander's best friend and a powerful witch, she'd use her magic to try and find Xander or fight against Spike. And Giles, too. He'd be the one providing knowledge and guidance on how to deal with a vampire like Spike who has kidnapped Xander.
Yes, they do. Their relationship develops in the comics.
Yes, they do. They have a romantic storyline in the comics.
They don't stay together. Their relationship has its ups and downs throughout the comic series.
No, they don't. Their relationship has its ups and downs but doesn't result in a final happy ending together.