1. In the Girl in Question Andrew told Spike (and Angel) to "move on and you might catch her one day"
I think that Andrew was being mostly just Andrew, the same as he was when he was telling the Potentials about his confrontation with Dark Willow in Season 7. And that statement, as well as his actions in general here directly contradict his "Buffy doesn't trust you," speech in "Damaged." I also think that it is quite significant that it is Angel, not Spike, who quickly finds someone to share his bed (Granted, "moving on" doesn't necessarily imply sex, but Angel was forming a relationship with someone who was quite obviously infatuated with him, which I think he saw as "moving on." Spike, on the other hand, remained celibate, even though undoubtedly Harm would have been quite willing to engage in a little friendly recreation.
2. Did your support of Spike/Buffy waver at any point in the series (TV or comics)?
Not really. The closest that it got was after "Seeing Red," but since, even then, I had a suspicion that it was a setup leading into something important, I just took the proverbial "wait and see" attitude.
lol, so yeah it was difficult for me to reconcile.
3. Prior to Season 6, do you think there was a believable time at which Buffy and Spike could have started a relationship without Buffy dying/getting resurrected and everything else that followed?
I've always thought that when Buffy re-invited Spike into her home and told him that she was counting on him to take care of Dawn, and his "'Til the end of the world, even if that happens to be tonight," reply was the tentative beginning of something very special between them. Also, I thought for just a moment that Spike's, "I know you'll never love me..." was going to lead to something very deep and tender.
4. What do you think was Buffy's biggest "green-eyed" moment, where Spike is concerned? Spike's, where Buffy is concerned?
For Buffy, I think that it would be a tossup between seeing Spike and Anya on Willow's computer, and the Spike/Faith bonding scene in the basement in Season 7.
Fof Spike, probably seeing Buffy and Angel kiss in the vineyard in Season 7 (If he had stuck around a little longer, he might have had his hopes lifted .'
5. Do you think Buffy and Spike have a residual kinky streak, post-Season 6, or was that specific to the circumstances?
I wouldn't call it actually "Kinky," as much as "Passionate." Up until Buffy was with Spike, we never saw any kind of passion that literally brought the house down or was destructive to the furniture. I can't even imagine Buffy and Riley under a Persian rug.
Buffy had, or at least REMEMBERED having, sex with Angel once, when she lost her virginity, and certainly Angel would have been very gentle and slow with her at that time. Farm Boy Riley always struck me as more the "sincere" type than as being any sort of super sophisticated lover, more of an athlete than an artist, if you get my meaning. He, like Angel before him, was too busy being in awe of the Slayer to attempt anything kinky, even if he knew of anything. Quite possibly, his storehouse of sexual knowledge was as sparse as Buffy's was at that time.
With Spike, for the first time, Buffy had a lover who was just as powerful and just as passionate as she herself, but could call on over a century of experience to enhance the experience. Passion and forgetfulness were what Buffy wanted and needed, not lessons from the "Kama Sutra."