True, although lack of air does nothing, lack of blood-flow does knock them unconscoius (Much like a solid THUNK to the head), and could conceivably deal brain damage.. But we'll leave that particular barrel of fish unshot.
For now, as to Spike's bad-assedness, yeah he's probably one of the best fighters around.. He's just extremely unlucky. He always seems to be the one who takes the big hit when a powerful baddy attacks. (Common fight scense usually include buffy+Spike rushing a monster, the monster knocks spike back, and while the monsters occupied, Buffy gets into range... Think of it like a D&D Attack of Opportunity, which allways happens on Spike instead of Buffy).
I think back to the first Spike V Buffy match.. If it hadn't been for Joyce and her Shovel, Spike would have 3 slayers under his belt, and Kendra would've been called half a year sooner.
*For those of you who haven't seen that Ep, this is a bit of a spoiler but seeing as how it happened 5 years ago I'm not doing the half-page Warning space for you.
Buffy and spike are kicking each others butts, eventually Spike gets the Slayer on the ground, helpless, and is on top of her, about to bite her when all of a sudden *CLANG* Joyce smacks him in the head with a shovel shouting at him "Leave my daughter alone", and causing him to stagger away.
I think Spike MUST be holding back, b/c lately XANDER has been doing better in fights than Spike has.. Ever since he got chipped he hasn't quite been the same (OK, when he first found out he could hit buffy that fight scene was pretty awesome, especially how it ended...

)
And to John Chricton - I know I speak for everyone here (And If I don't speak for you, don't bother telling me as I like beleiving in my own omniscience.. hehe) when I say "PLEASE GOD LET THAT BE TRUE!"
I don't know what they'd do without Buffy (Although some of those potentials seem to be fairly good actors, and MAY be able to take over...), but I'ld be partial to a show called "Spike"

Or more appropriately, maybe they'd just start a new series called "Sunnydale"?
So many concepts they could work with, but I just don't know if it'd work without the originals... It got a bit weird when Giles left, and only now that he's back is it feeling like the right show again...
OH well, as long as we keep ONE of the shows I'll be (slightly) satisfied.
Pls don't go, Scoobies!
OK, that's my rant.