Huh? What part is least symbolic?
Keep in mind that in accord with natural philosophy, Elemental Fire is not the same as physical fire. Physical fire is among the most appropriate representations of Elemental Fire because it's qualities are quite similar, but they're not the same thing. When one speaks of Fire (I use proper case deliberately to distinguish it from physical fire) in the context of natural philosophy, one is talking about a philosophical concept. Specifically, arche, or what the fundamental substances are that underly all of reality (to which other approaches are monism or dualism, for example). Empedocles proposed these were four, and the idea was expanded on by later philosophers, especially Aristotle. My understanding of the Four derives principally from Aristotle, but also other natural philosophers throughout history.
From that perspective, there is little doubt that Fire is the most warsome because of its qualities. Just as Elemental Fire doesn't refer to physical fire, when I say Fire's principal quality is hotness, I don't mean physical hotness either (as that's not what the philosophers meant). It basically means an active force that separates and differentiates. How I see physical fire is very much influenced by how I see Elemental Fire, which is why I have a hard time seeing fire's prevailing characteristics as... well... peaceful. Separation and division is the very fuel of conflict and war. Other things too, of course.
Elemental natural philosophy aside, if we're talking physical fire, I cannot overlook the fundamentally destructive nature of fire. Fire burns. Even when it is contained and controlled, it burns and destroys. The candle flame consumes the wax, the bonfire consumes the wood. And if you immerse your body in fire, you die. Fire is a tool of the aggressive. It is used as a weapon, and it forges weapons. I can't overlook things like that.