A quick thought as I take a brief breather from dissertation writing…I agree with your main point very much. I wish to raise another question:

Could it be that “baptizing” in the sense of redeeming/transforming something from culture simply cannot be done with some things? Take Ultimate Fighting for example. I don’t see how this can be redeemed, or be redeemed and remain what it is. In that sense, then, it must simply be done away with for the Christian, and left behind as part of the old life.

Redeeming things in the way that God has redeemed in Christ involves doing away with the old and bringing new creation into existence (or at least beginning this process–already but not yet). I think you would agree with this generally (or perhaps not!). I think (at this point, at least) that with some things in culture this baptism of redeeming/transforming cannot be done; only the people can be redeemed and as new creations walk away from those old and dead/dying elements of culture. I sometimes use a silly analogy with my students: the good news of Jesus Christ is not different or new jelly to fill into an old donut, but an entirely new donut.

Kyle