The story was going well untill chapter 4..........then Buffy meets Spike and it's like you ignored your whole set up and put them in the original season 5/6 together with bitch Buffy smacking him around and Spike taking it with a "sheepish" expression as you said. He may be unable to hit back but why would he be so apologetic and sumbmissive, especially with her awful attitude.

Author's Response: What's important to remember about this Spike is that he's far more connected to his human friends than the Spike of the real BtVS. He loves them all, to some degree, and his reactions here are far less defensive and more laid back and accepting. Someone once described him as the "heart" of the group, and that's really what he is here. So he's going to react differently to Buffy, not because he's in love with her but because he's in love with the people she's been sent to help.