I've been staring at your particle effects for dozens and dozens of hours because I've been working on a mod for them for a couple weeks. Your particle engine does have some glitches, it seems like there might be some sort of throttling for the number of effects displayed at once.
The Ravastra Skirmisher seems particularly prone to this problem.
Saving and reloading the game can temporarily fix the problem if it occurs.
Sometimes particle effects will not display when they should. Sometimes you will be cheated out of an explosion, but that's fairly rare.
It's extremely common for the muzzle flash and weapon impact effects to get out of sync with the projectile fire.
I'm not sure, but the amount you zoom in seems to affect this. It may be the case that the likelihood of seeing impact effects play is greater when you are zoomed in on them more, or perhaps looking at other effects less.
Also, you may not consider these problems, but:
The engine will glitch if you attempt to put in a texture animation with more than 20 frames. Any frame past the 20th will be corrupted.
There is no consistent sort order for nonadditive effects. The order that they are rendered is random with respect to the order that they are listed in the particle file.
Rapidly moving particle velocities appear glitchy and jumpy, as though they are undergoing discrete rather than interpolated motion.