Additional Note (since i'm not sure if it's possible yet):
3) Adding the option to add a border around everything (not the current particle-emitter)
3b) adding more border options (i.e. having a 2px thick black border followed by an 1px white border) -> important to be able to change the order/zIndex
3c) (not sure if possible yet) adding the options to use a fill on everything (with different blendmodes). This would allow to easily tint the whole animation or reverse colors.
Thanks!