I see your point Phillip. My view though is that the fall of the Balrogs has more to do with Melkor's fall than with the flawed idea of building the Lamps. If we connect the fall of the Balrogs with that idea, we somehow make the Valar responsible for their fall. Not much but enough to make it a bit problematic I think. Also, I feel it would make the moral aspect of their fall somewhat unclear. I would like the focus of the process to be how they accept to have Melkor stirring up hate in them, and on how they let this hate lead to the aggression of destroying the Lamps. This is represented visually and physically by their fair beings of intense light burning, resulting in the ruining of their wings (and looks, generally) and consuming their power partially - the bright fire becomes just a red hot one, mingled with shadows.