nice mate, loved the bit about the paticle shader,
i tried to get some opacity at birth because the 'sparks' were coming from the cone rather than simply from the tip.., hence the soft look on one of the jpegs.., i needed to write a creation expression for opacity based on age ..., but was just showing it could (your example) be run on a motion path.., meaning i think you have answered this one with gusto
cheers dude.., more people such as yourself (there are some around) and the world would be a better place
take it easy and life will be easy