As a Physicist, I am wary of making such statements since they put the cart before the horse ( http://en.wikipedia.org/wiki/Teleology ). I'd be more comfortable saying "In a fluid, we have vortices... as a consequence of the movement of material and energy."
In your case I'm assuming it's just a turn of phrase, but there are some hypotheses which actually attribute abstract "goals" to nature, without providing any explanation in terms of mechanical processes; for example http://www.lawofmaximumentropyproduction.com
In constrast, Darwin explained the theory of evolution using the mechanical process of natural selection. The principle of least action can be explained either physically, using quantum interference (eg. in optics), or mathematically, due to the mixture of inductive steps with deductive ones.
In constrast, the existence of vortices in fluids because of their efficiency would be like claiming crater lakes can't exist because water flows downhill.
Compare your electrostatic sphere example to my crater-lake example: lakes at a high gravitational potential are inefficient, it's less costly for the water to flow up the sides of a crater and down into the ocean. The reason that doesn't happen is because there is no mechanism for it to do so. If we look at liquid helium, there is a mechanism which allows it (the Onnes Effect) so it does happen.
> Electrostatic forces keep the surface of a liquid as taut as they can
Yes, but the interesting part of the sentence is "as they can"; we can't just assume that a liquid's surface will be at minimal energy, since that would allow us to solve NP-complete problems with soap bubbles ( www.scottaaronson.com/papers/npcomplete.pdf ) :)