There's more than one way to look at most anything -- I thought it was clear that I was merely stating how I look at it! ;-)
So is Judaism. The difference is that the Jews are the ordained clergy-nation, while the Gentiles are the Noachide congregation.
Judaism got to that point, but it didn't start out there, and progress was . . . let's say "uneven."
When St. Peter tells his audience "you are a priestly nation" who is he addressing, given that he was an apostle to the circumcision?
I'm not sure what your point is here.
I'm not sure what your point is here
The point is that St. Peter was addressing Jewish Christians as the priestly nation. Remember, Jesus was sent, in his own words, to the lost sheep of Israel only, and he defines the lost sheep of Israel very clearly as not Gentiles and not Samaritans. I know, Matthew 28:19 suggests otherwise. That's another issue.
Judaism had a place for Gentiles as well as for the Jews ever since the Great Flood, when God gave all humans his seven Noachiade Laws to abide by. Gentiles are not held to any other task. They are to be the congregation and the Jews the priestly nation required to do what priests do.
The idea of a universal priesthood is a latter day development (a work in progress as you call it) that was necessitated by the turn of events that saw Christianity condemned as an apostate sect, kicked out of Israel, and left to itself to survive. Which it did, by becoming a hallenized religion acceptable to pagan Greeks and Romans.
I know this is not what they teach in Sunday school. That would be counter-productive. But the history tells us otherwise.