When i (not infrequently) get offended it is almost never because i feel personally diminished or threatened. I have very little institutional status and that doesn't bother me much anymore. I take offense at disorderly conduct and/or thinking, perhaps on behalf of a sovereign i wish others would better respect. If i call someone a nasty name, it is a way of pointing to the sacred and saying "you're out of bounds", or your conduct threatens our ability to defer violence. So while i appreciate your call to desaturate liberal space and to consider better ways to respond to threatened reciprocity, i can't help but wonder if your claim that taking offense is useless is akin to claiming resentment is unnecessary.
But you think about what would be the best nasty name to call them, I assume. And you might decide to take offense at one interlocutor rather than another, and could give reasons why. (You don't lash out indiscriminately at the latest offender.) In other words, there's judgement involved--the point is not just to incite an equivalent resentment in the other, in anticipation of some showdown. If so, I would say that your taking offense is, as you say, a resentment on behalf of the center, and it leaves the sphere of resentment/offense as soon as possible by invoking the authority that defends what are today the at least nominally established limits on expressed resentment. Resentment may be ineradicable, but it can be made intelligent through donation to the center.