Ballista will enjoy this post, although I still disagree with some of his arguments.
I wrote previously on the argument that kephale in particular is not exousia in marriage: Headship is not authority in marriage, Headship is not authority in marriage Part 2, Headship is not authority in marriage Part 3.
Having done more research on all of the instances used on kephale in the Scriptures (of which there are 76 times it is used), I conclude that headship is authority in marriage.
God brought to mind a clarification on the argument I was discussing. The “ability to punish” which is an innate part of the authority-obedience relationship of parents and children is quite different from the authority-submission and kephale-submission relationships. This is where I disagreed with ballista’s use of paideuo which I still do regarding the authority-submission and kephale-submission relationships.
However, having already understood that authority is good, the fact that authority may be abused is not a rational reason to dismiss authority. Though, my argument was not based on dismissing authority but rather clarifying the intent, even though you can make the argument that Christ does the same thing with His humility toward us in Phil 2. Hence, why I still believe it to be a sin for a husband to directly punish his wife**.
Thus, understanding where the line or boundary of a specific position is drawn does not change whether something is good or bad as that has already been determined by the heart and actions. For example, I could say that the position of sales clerk has X, Y, and Z responsibilities. That changes nothing with the fact that the clerk would never be permitted to steal which is a moral issue unrelated to such responsibilities. The two actions are unrelated to each other and relating them to one another is implying a relationship where there is none. Therefore, understanding the nature of headship and all of that entails is directly related to understanding the nature of God irrespective of any actions.
Thus, headship and authority are one in the same, and they are both good.
Additionally, regardless of whether a husband weilds the authority to punish or not in marriage or even whether it is a sin itself, the wife is still to submit to her husband as the head. This is why it does not matter in regard to the relationship if the husband weilds such authority or not; the duty of the wife is to be in submission to her husband out of respect for God and her husband.
This is why sovereignty of the husband means nothing in marriage: you can’t force someone to submit. Which is why it is of supreme importance that a man vet a woman thoroughly prior to marriage.
** Note: there is a difference between consequences and punishment. Consequences are directly proportional to the actions. Authorities have the right to impose consequences. For example, the government imposes speeding tickets for speeding. Elspeth provides the example below in the comments about husbands removing credit cards because of the fiscal responsibility that is placed on the husband. On the other hand, punishment is unproportional to the act, and often done out of spite. Obviously, doing things out of spite is not what the Father is about nor should Christians be about.