Spike. Short fuse, check. Impulsive and can't be bothered to be a chess master, check. I'm not a punk but big post punk and grunge fan who happily threw themself around to Pretty Vacant in a club, that's close enough check. Bolshy yet insecure, check. Willing to defend what I believe in tooth and nail, check.
It's not wish forfillment as I'd rather be Giles and I also have Andrew's ability to want to run away play in the world in my head and I think we're all Andrew to greater or lesser degrees in being fan people obsessed. I may be a bit Xander like to although I'm much more academically gifted and less good at making things.