Yup, still really bad. Like last time. This time, I'll give you tips though:
Fire doesn't move when the source moves (your pillar of fire moves like a stick from the front of the paintball gun). Instead, it emits and then moves independently from it's environment. If you were to, say, composite a blast of fire coming from an actual flamethrower in there, it might look better. In fact, always use actual footage of things in your composites.
Spread: fire doesn't come out looking like a stick either, it spreads out and billows.
Smoke: Where is it? Fire makes smoke. And find real smoke.
Effect on Environment: The area around you should light up in relationship to the position of the flame.
Finally, color correct the entire image to make everything look cohesive. An overall correction to add some style, but also correct each individual element in the composite UNDER that final correction so they all look like they're supposed to be there. Look at your natural lighting (and light quality), and adjust according.
To wit: http://www.videocopilot.net/blog/wp-content/uploads/2010/09/Blog_Outtake_web.mov