I still haven't found an explanation of priesthood keys I feel hits the nail on the head. There are many discussions that make one good point or another, but that is not what I am after.
According to our church handbooks the EQ president holds keys, but the high priest group leader does not. Presumably this is because the EQ president is the president for a quorum, and the high priest group leader is not (as the president of the high priests quorum is the Stake President).
But where does this information in the handbook even come from?
And who understands it? I have yet to find someone who could explain what keys an elders quorum president holds that a high priests group leader doesn't, except to observe that one is the head of a quorum and one is not. But no one can explain what effect that has, what difference that makes. If holding keys makes no difference, then we don't really believe in keys.
In D&C 110 Moses appears and restores the keys of the gathering of Israel and the restoration of the ten tribes from the lands of the north.
Now this does pretty clearly refer to missionary work. That is how Israel is gathered. But missionary work had been being done for years before this marvelous manifestation. How did the restoration of these keys change things?
We can hardly answer the most elementary questions about priesthood keys. I think that is an embarrassment to us to a degree, myself included. But what can we do, but repent and get to work asking, seeking, and knocking as the gospel requires.