Neirao: Good workaround and nice result for the fire. As far as the rocket trail goes, a better result can be obtained if you apply 2 different materials i.e. fire and smoke.
Rellik420: I think the graphics are pretty self explanatory. However, I will try to explain it like this.
When we export the terranim8or fire project to an anim8or file, you get an object, which replicates itself into a number of copies in scene mode and all these objects move in a scripted manner in predefined paths to give us a flame effect. However, if you look at the orientation and paths of these objects they move in one single plane only. So, the trick is to alter the plane and orientation of these objects in scene mode by rotating them so that they do not move only in one plane, but rather scatter and overlap each other.
For interested viewers, here is my attempt at realistic fire some months back.