Niagara questions

Hi all,

I am trying to tweak some overall settings from a scene I am making. I took out the aircraft for a number of reasons but I think you will get the idea of whats going on.

I created one fx and copied it, but know they all look the same. I want to tweak it so each one is a little bit different I want more variety. Do I have to create 5 different fx for that or can I just have one fx? If so how would I go about doing that?

On the overhead camera its looking a little sparse at times. How do I get it to be a bit fuller?

Also on the last shot it looks like me fx is popping on. How do I change that? Is that the size of the particles or the speed or something else.?

Thanks for the time everyone.