Mosiah 2:11 - 2:15

Mosiah 2:11 But I am like as yourselves, subject to all manner of infirmities in body and mind; yet I have been chosen by this people, and consecrated by my father, and was suffered by the hand of the Lord that I should be a ruler and a king over this people; and have been kept and preserved by his matchless power, to serve you with all the might, mind and strength which the Lord hath granted unto me.

King Benjamin is a man, nothing more. He is no better than any other man born on this earth. He can get sick and feel pain. His position as king was given to him by his father and the Lord allowed it to be. He had no special gifts that gave him the right to rule. But the Lord has supported him in so much that he was able to lead his people in a manner pleasing to the Lord. He's allowed king Benjamin to serve his people using all his talents and abilities. It was not king Benjamin’s natural talents that gave success to the people, but the Lord supporting and inspiring him in his position. He gives the complete credit to the Lord for whatever success he achieved as their king.

Mosiah 2:12 I say unto you that as I have been suffered to spend my days in your service, even up to this time, and have not sought gold nor silver nor any manner of riches of you;

King Benjamin testifies that he has not sought for any sort of recompense for his services to his people. His whole efforts has been to serve them as best as he could, nothing more.

Mosiah 2:13 Neither have I suffered that ye should be confined in dungeons, nor that ye should make slaves one of another, nor that ye should murder, or plunder, or steal, or commit adultery; nor even have I suffered that ye should commit any manner of wickedness, and have taught you that ye should keep the commandments of the Lord, in all things which he hath commanded you—

His laws were such that he would not allow people to be put in jail. No one was allowed to make a slave out of another. Taxes were to the absolute minimum. Lawlessness was not allowed in any of its forms such as murder, theft, immorality, or any kind of wickedness that may not be specifically defined in the law. He had encouraged the people to live the gospel and to adhere to the law of Moses.
[Clearly the combination of church and state. The law of Moses was the standard and the state enforced the law. Not sure what was meant not putting people in prison. Maybe referred to exiling people from the community rather than putting them in jail or it could be that crimes were punished by repaying the victim more than what stolen or they would be banished from the society. As far as making slaves of people, I think that refers to people being indebted to another. I maybe that if a person had a good reason to borrow money, it may have just been given them or they could pay it back when they could if they could.]

Mosiah 2:14 And even I, myself, have labored with mine own hands that I might serve you, and that ye should not be laden with taxes, and that there should nothing come upon you which was grievous to be borne—and of all these things which I have spoken, ye yourselves are witnesses this day.

To further testify as to his righteous treatment of the people, he has not collected any sort of payment for his services as king so that the people could not accuse him of living the high life off of them. All of his actions in relation to his kingship is well know to everyone.

Mosiah 2:15 Yet, my brethren, I have not done these things that I might boast, neither do I tell these things that thereby I might accuse you; but I tell you these things that ye may know that I can answer a clear conscience before God this day.

King Benjamin tell his people these things about his conduct towards them. He does not do so in order to boast of his personal goodness. He does not do so in order to show how depraved they are because they do not come up to his standards of conduct. He starts he speech only to point out that what he will say he can say because he has no guilt because he did not take advantage of them or force them to submit to unrighteous dominion. He has spent his entire reign trying to serve them as best as he could and he has not done so the make himself rich or more powerful.