well you present some very valid points (and no im not anyones fanboy) but you also assume with a good bit of your arguement that minato would stand there with his thumb up his ass if his first strategy failed. He hasnt been spoken of as a master strategist, i think because he hasnt really encountered anyone needing the usage. Either he epicly pwns them or some form of interference ends the battle prematurely. For instance you said, naturally he would teleport to the nearest kunai, and simple deflection could prevent him from setting up kunais to surround an opponent. Well after a bit of realization, how do we know he wouldnt purposefully move to less advantagious spots with the actual purpose of placing kunai all around the fighting area (and please no one counter with "well he could just run to a different place" because anyone with speed could run to a different area) that said lets assume they stay in the fighting area. If he then takes the time to "foolishly" as some might say move randomly to place more kunai, he would then in fact have the opponent surrounded. Another factor, and correct me if im wrong, but teleporting to me, insinuates that he doesnt move quickly but actually rematerializes at the chosen spot, while sharingan could slow the movements of even the fastest ninja, unless kishi wrote elsewhere that it can, how can it keep up with something that literally takes you from one spot to another instantly, not close to instantly but truely instantaniously? It can keep up with any movement i'll give it that but a teleportation isnt movement in the sense of running fast. While my arguement doesnt prove it to be the godly tech that some make it to be(that wasnt my intent) im just saying, its not as useless as you make it out to seem even against high level ninja. Short of a very good genjutsu, none of the abilities of the sharingan have much effect unless minato is just standing there.