Everybody on the stupid train!
These videos are actually on Liveleak, not YouTube, but I figured I'd diversify my search. I'm still calling the files youtube for simplicity.
Ass poppers - Homoeroticism is occasionally a part of fireworks misuse for some reason (butt rocket anyone?) but this is the best example yet, even if poppers aren't technically fireworks. It's like they are taking turns spanking each other, and I'm sure somebody watching is getting off on it.
General stupidity - Including a butt rocket reenactment. Seriously, who sees that and decides to try it for themselves?!?
Santa Suicide Bomber - Ok, I'll admit this one is actually pretty funny. That giant robo-Santa is creepy, so I was happy to see it be destroyed, but the people doing it were a little close...
This video shows a Chinese fireworks factory back in the day, I'd guess the 60s, but what do I know. The basic techniques aren't much different from the ones in the last video I posted about, which has since been removed for copyright violation... It is cool to see what things look like, and you'll notice back then it was men working in the factory, still wearing more traditional clothes. Seeing the performance of the fireworks at the end is interesting because they really aren't all that good, but it doesn't stop that girl at the end from loving it!
Here is a cool video of time lapse photos of fireworks in Bellevue, WA, just because.
Finally, a page showing consumer fireworks in Japan. They are apparently sold year round with no age limits, which is almost hard to believe. Perhaps like in the US, it varies by whatever the Japanese equivalent of states and counties are. The fireworks are interesting and seem to be mostly fountains, although there is mention of ball shells as well. I'd love to see some video of some of these items (there is one of the sparklers).
I think all three of these were posted by various people on PyroU, so thanks whoever you are!