I'm not sure about that one. I never thought to try on other bosses or mobs or such back when I found it.

I don't know the specifics, I've never done a speed run of GDL before. Been considering doing it one day when I get a capture card that actually works, so was just a bit curious. :)

I can confirm that it does give boosted XP though. From my comparison when I killed normally at lv.50 the boss leveled my toon to 55. When I killed normally a second time I went from 55->56. When I killed with SS only I went from 56->63. This is really the glitch I had been asking about, but it sounds like it's OK and not really something that would end up being used.

Are there any rules or regulations for using the Spider Queen glitch to speed level on the GameCube version of the game. Which speedruns allow it and which do not?

For those of you not familiar with the glitch. If you go into the Spider Queen fight with multiple stacks of Super Shot you can kill the boss without ever being in danger of taking damage. A side effect I found, way back when, was that doing so makes the game think that you're killing the boss at a much lower level than you actually are. You can do this a couple times in order to skyrocket your character's level+stat. As a side note: you always make enough money at the end of the fight to refresh your Super Shot stock.