Heya, thanks for the input!
I'll look into extra shapekey options in the future, that's some great input, though I'm not 100% sure how I'd go about making it longer, the SPS plug might also have issues with that, but I have to look into if that involves bone scale or if it'll be fine if I alter the position of bones instead.
As for shoot, I'm not sure, I've noticed that too, it might have something to do with their particle setups, did you try placing just that emitter further back than the others?
It shouldn't have any sound that I know of, wonder where that one's coming from - but cumflation sounds like an interesting one to add as well!