Well I definitely love this script, it really makes explosions that much more awesome. Using 7226 though it seems like there are some things that don't work as intended.
+Speed and +Size both can take two integers, a Max and a Min value, and as I understand it the actual speed or size is supposed to be randomized for each particle-trail-emitter thingy. It's not; as far as I can tell only the minimum value is ever used.
Also, weapon creation... doesn't really work. I tried to have a simple near-invisible corkscrew weapon with a large trail attached, and so much stuff went wrong that I can barely describe it. Now that I scaled the particles down to a reasonable size, they're emitting downwards at a ridiculous velocity (I never specify any of the velocity or spewcone fields) on the first cruiser's explosion and dying after one frame in the second cruiser's explosion.
[EDIT] It seems weapon generation is screwed up for corkscrew or swarm weapons, and those are really one of only two reasons to emit weapons in the first place.
Also, these particles being rendered next to flaming debris shows that these are much denser than flaming debris trails. A way to customize particle density in emitters would be nice.