Q 263:
If a troll (which has 63 hp's) takes 67 points of fire damage (thus putting him at -4 hp's), does he auto stabilize (because the HP loss while dying isn't fire or acid damage) or does he risk bleeding out (because the loss of hit points in this instance isn't technically classified as "damage," [unlike the point of damage taken from strenuous actions while disabled] and thus isn't treated as nonlethal for the purposes of regeneration)?
As long as that much damage isn't dealt by fire or acid, he's probably okay (operative word being probably - this assumes he doesn't have fast healing of any sort). As a rule of thumb, critters with fast healing/regeneration don't stop healing when unconscious. Lemme dig up Rules Compendium for precision though.
EDIT: No specific mention. However, given that the rest of the regeneration entry mentions that an unconscious, regeneration-capable creature can only be Coup de Grace'd with an attack form that destroys its regeneration, I'm pretty sure it doesn't bleed out.