You, having ears, hear not; having eyes, are yet blind.

There is no attitude of haughtiness in excommunication or disfellowshipping. It is an act of discipline designed to bring about repentance and conformity to God's Word. You do understand discipline, having been in combat and all, don't you, jr? Sometimes it's unpleasant (as most discipline is), but if properly applied, is not attended by arrogance, haughtiness or any other such unscriptural attitudes, which would make him as guilty as the one with whom he is refusing fellowship.

It cannot "backfire" unless the person withholding fellowship is in sin himself, and his hypocrisy is exposed. That would serve him right in my view.

If Biblically done, it is not "cruel and childish" but rather the opposite: It is loving and mature. It is designed to bring someone to correction (which is a loving act) as a spanking to your child to correct his behavior.

No. I have not served in the military. This is a smokescreen for the real issue. That is, any scriptural principle can be practically applied.