I'm not quite sure I see what you are saying. Let me give an example of one way I understand the passages I quoted from the D&C. I use these verses as a guideline for how I raise my children. God expects me to influence my children for good. If I don't try to influence them, I'm not doing my God given job. I assume you would agree. I should therefore do and say things that influence or encourage them to make good choices. There are godly ways and ungodly ways to go about this task. This verse describes the godly way and says there is power, meaning righteous power of influence in doing it God's way. If I use force, anger, or unrighteous dominion, the Spirit of God will withdraw from me and I will not be effective as a father. That's not the Lord's way. However, if I use patience, brotherly kindness, and love unfeigned, the Spirit of the Lord will be with me and I will be effective. Of course, none of this negates my children's free will.
I see your misunderstanding. I think you have an incorrect view as to the godly way of being a leader. For example, in respect to your children, God teaches you the correct way to raise them, but you have effectively NO POWER over the course of their life. That is completely between them and God. That is one thing that I think is so frustrating about being a loving parent is being able to let them make decisions for themselves.
So, as a leader, God GRANTS us authority and power, but we must recognize that it is God alone that works THROUGH us, and that at any moment that power could be taken away from us. This is not determined by whether or not we are GOOD or RIGHTEOUS, but by God's Will alone.
Job was a righteous man, but God took everything away from him. His (poor) friends argued that this was because he was in fact not righteous. The reality was that God had his own plan for Job and was able to make his walk with God stronger than it was before.
If we equate 'power' as a measure for 'righteousness', we remove God from the equation. That is what I am trying to say. It is not correct to say that if we are bad God will take away the Spirit and thus all his blessings. This is simply not true. Unrighteous people are gifted with just as many worldly blessings as the righteous, if not more!