Just a few thoughts in regard to this e-mail.
Remember the responsibilities of an Elder. “An apostle is an elder, and it is his calling to baptize; and to ordain other elders, priests, teachers, and deacons; and to administer bread and wine – the emblems of the flesh and blood of Christ – and to confirm those who are baptized into the church, by the laying on of hands for the baptism of fire and the Holy Ghost, according to the scriptures; and to teach, expound, exhort, baptize, and watch over the church; and to confirm the church by the laying on of the hands, and the giving of the Holy Ghost; and to take the lead of all meetings” (D&C 20:38-44). This obviously extends beyond that of the family. Their duties are expounded further as the section continues, but are to be aided or expressly done by the lesser priesthoods if they are present. If not, the elders do them as well. This revelation was given before the wards and stakes were organized. It is my understanding that our elder responsibilities exist only in our ward. So, to individuals within our ward, we have the responsibilities given to us above. Of course we don’t take it upon ourselves, but we are assigned to these responsibilities, particularly through home teaching. Accordingly, we must be set apart for special occurrences outside the ward. Just like stake leaders have to be set apart for the stake level. But an elder is not set apart for their home teaching responsibilities. Assigned, but not set apart. As missionaries we had to be set apart as a missionary to have the revelation and privileges necessary to be a missionary. I have always found it interesting that our stake president sets us apart rather than the mission president. I don’t have an answer for that one yet though.
So according to my understanding of the Melchizedek Priesthood, we are responsible specifically for our families and those we are assigned over. But in general you are privileged to exercise those powers for members within your ward without a special dispensation from the heavens.
Now as related to extended family, I do not believe you can receive revelation for them. Nor will you be responsible for them. However, you can still teach the gospel in its pure form and answer their questions accordingly. You cannot counsel them individually or according to revelation, but you can according to your inspiration and understanding of the word of God.
Be careful comparing yourself to these individuals who you are comparing yourself to in Jacob 1:19. They were to high priests over the whole church. Of course they were responsible for them all. But you are not. They would answer for all their sins. Just like President Hinckley is accountable for the entire world! To teach them according to the word of God and with all diligence. But we are home teachers and our stewardship is more limited compared to President of the church.
As for what is appropriate to teach. I think that is one of the reasons why the Lord gives the commandment that we are to speak nothing more than repentance and to teach the word of God. Even missionaries have very limited roles in which they can receive revelation. They are given just enough to find the humble, to lead them to the waters of baptism, and that is it. We cannot receive revelation on much more for our investigators. After all, that is the Bishop’s role. Don’t forget he is over member and non-member. We are there to aid the responsibility of the elders already in that ward and stake. We are not in charge of it. The mission president meets with and counsels with the Stake Presidents concerning the work. Only where there are districts and branches is the mission president over the work.
As concerning milk and meat. You can give what he asks, and only according to scripture. But you know that your job is first and foremost to teach faith and repentance. Our key is in D&C 19, “and thou shalt declare glad tidings, yea, publish it upon the mountains, and upon every high place, and among every people that thou shalt be permitted to see. And thou shalt do it with all humility, trusting in me, reviling not against revilers. And of tenets thou shalt not talk, but thou shalt declare repentance and faith on the Savior, and remission of sins by baptism, and by fire, yea even the Holy Ghost. Behold this is a great and the last commandment which I shall give unto you concerning this matter; for this shall suffice for thy daily walk, even unto the end of thy life” (verses 29-32). It seems very direct that this pattern is for preaching the gospel, and is enough for our daily walk to the end of our lives. We can chat about these things, but are to keep it according to the scriptures, and not more. Perhaps too many of us are talking about deeper things when we are not exhorting faith and repentance enough. Like President Cherrington always used to tell us, “gospel curiosity will not save us, but living the gospel.”