Yes, we certainly agree that pursuing worldly, conventional power within the framework of our current demonic, totalitarian system is not conducive to being a Christian.
Furthermore, recognition of this must trump all "good" motivations to "do good" at the societal/political/economic level. No matter which way you slice it, there's really not much a Christian can do or should do within current power structures because all are blatantly calibrated for destruction and damnation. Christians who aim to assume positions of worldly power within the current milieu will likely end up unintentionally exacerbating and amplifying the coercion, manipulation, lies, violence, etc.
When Christians think about power -- and I think they should because to consider oneself powerless is a self-defeating and despairing position -- they should do so primarily at the (inner) spiritual level within a personal context that is outwith the System, which is exactly where authentic power exists.
We should focus on connecting to God, reality, and others in a manner that recognizes that true power resides in these connections -- in these kinds of participation (to borrow your phrase from Barfield) -- and that these connections influence the world and eternity in ways coercive worldly power cannot.
To return to a point I meade in an earlier post about power -- we really need to wrap our heads around the reality that Jesus IS more powerful than the worldly powers that crucified him otherwise we can never hope to understand that we ARE more powerful than the worldly powers that harass, coerce, and manipulate us.
However, as you stated in the excellent comment you left on that post, this "requires that we consider the spiritual as well as material, and eternity as well as the duration of this mortal life."