Thanks for helping our readers with regard to "the noble savage." The distinctions you draw are on target. In my post, though, I had in mind a popular notion that enjoyed considerable popularity during the colonial period and even throughout a good bit of the 19th century. So...our discussion has now identified three takes on "the noble savage."
I've always found Walter Wink's perspective on the powers persuasive and a fine lens through which to examine Paul's statements on the subject.
We may disagree on one matter. You state that if we are called to confront the powers, we must also have the capacity to do so successfully, else the entire thing is futile. If I'm overstating, feel free to correct me. From my perspective, and I think this would be true of Christian thinking as a whole, this is not necessarily the case.
I don't think it too difficult to conceive of situations in which we might well be called to go up against a power beyond our strength to overcome. In such instances, we would be responsible to go as far as our wisdom and endurance allowed. At some point, the greater power would break or defeat us. We might truly be said to have failed. Yet, it would be still right to try. My tradition teaches that such "failure" may actually lead to consequences that ultimately bring down the power in question, or at least set it back.
If you want an example of this kind of thinking, consider The Lord of the Rings (and, yes, you really need to read the book). Frodo, the hobbit, finally breaks under the pressure of the ring's power and his own suffering and so fails. His failed quest, though, has managed to bring the ring to the one spot where it might (just might) be unmade. At that point, things happen that are beyond his control or imagination, and his failure is redeemed by the destruction of the ring. The resurrection plays a similar role the story of Jesus.
Well, we've managed to take flight and range over a wide territory during our discussion of the commandment. Perhaps you can bring us back to earth!