What has been the problem has been emulating the gentle glow that fills almost the entire bag when those burners light off in the dark, and the existence of a "flame object" doesn't seem like it would be of any help in that.  That's such a cool thing to see in person that I'd like to realize it as closely as possible in my animation.

I tried the idea I'd proposed in the last paragraph of my previous message, and it comes kind of vaguely close, anyway.  I'd still like to get closer, but at least I feel like I'm in the ballpark now ... maybe it will do the trick after some additional refinement.  However, I remain open to any brilliant notions that anyone might have.  I'm still working with a sphere primitive for testing it today, but before the end of the weekend I figure to try a render with one of my actual balloon models ... when I do, I'll post the results for your comments.