I really enjoyed this, and would love to read more, if you continue with it. The rambling monologue seems very much what Xander would do without the reactions of others to respond to. I can see Giles listening to this and trying to resist the urge to keep him to the point. Xander obviously can, as well. ;-)

I like the fire element vampire notion, and that it shouldn't really work, but then it's Spike...

The feel of the land, and Xander's reaction to it, his compassion, and his maturity all came through so well, as did the feeling that Spike, for all his changes, is still Spike.