Another thing that occurred to me as I was reading these chapters is the fact that Buffy is still in college. Now, it's been a long time since I watched S5, but the fact that Joyce is recovering from her surgery, Buffy is once again working for the Council and Riley is gone, then surely Buffy would have already quit college, as she did in S5, when she realized that her mom was sick and everything that was was going on with Dawn. Yet, Golden seems to be operating in a vaguely AU version of S5, with no Riley, but also no Key-ness or Glory either. A lot of the other books I read that are set earlier in the shows run stick pretty close to canon - there are passing mentions to Dru and Spike (and Angel, if it's later in S2) as though they've been light on the evil front while the gang deals with the antagonist of the book, They talk about the Mayor and how they have to keep watch for him, just in case. I don't know how I feel about Golden here picking and choosing the canon of S5 he wants to deal with. Unless I haven't gotten to the part of the book that does mention Glory and Dawn's Key-ness, it just bugs me a lot that he's glossing over so much of what made S5 what it was.
In these chapters, what surprised me most was how off Spike sounded. His banter and interactions with Buffy came across as stiff and wooden, like the author wasn't that comfortable writing for this character. Spike sounded more like a caricature than the character I know and loath, and it occurred to me that maybe that's because Golden wasn't used to writing Spike as a not-bad-guy (I'm reluctant to call him a good guy within the scope of this story, as I don't think he is). Off the top of my head, I can only remember five other novels that Golden has written: Dark Congress, Monster Island, The Gate Keeper Trilogy, Spike and Dru: Pretty Maids All in a Row and The Lost Slayer.
Dark Congress - Set after the series finale, and - if memory serves - Spike is considered dead.
The Gate Keeper Trilogy - set in S3, no Spike
The Lost Slayer - set in an alternate S4 (REALLY alternate) Spike is a henchman of the Big Bad
Monster Island - off the top of my head, I don't remember Spike appearing at all
Spike and Dru - while being one of the main characters, he's still the major bad guy of the story
Perhaps Golden just wasn't used to treating Spike as a white hat and therefore didn't understand how his interactions with Buffy took shape. Considering, again, that Golden seems to be choosing his own canon for this story, Spike's feelings for Buffy seem to be a non-thing, and so Golden seems to be basing their conversations on S4 and nothing more.
Also, when did we ever hear Buffy use the word 'marvelous'? That sound really out of character for her.