It is worth noting that Eliphas Levi's exploration of the inverted pentagram/pentacle is somewhat unique. Up until that point it wasn't really associated with evil beyond its associations with magic.
Upright, the pentagram is often a symbol of invocation, where as inverted it can be used sometimes as a symbol of banishing. It should be said that the pentagram, even when upright, can be used in banishing. The Lesser Banishing Ritual of the Pentagram is a good example of this.
In general terms, the pentagram does represent the elements. The four lower points are the elements, where as the fifth point represents the spirit, or the divine, and its influence within all things earthly and spiritual.