I wasn't sure what to make of all of this, so I kept reading these chapters and studying the underlying principles.
Since that time, I've noticed many of the same themes in 2 Nephi 9, Moses 6/7, and D&C 29.
I'm still uncertain what this means, and so I present it here without a big overarching conclusion. In each case, a prophet is either teaching believers or struggling quasi-believers.
I've thought a lot about the best way to present what is a vast amount of information, and I've settled on just displaying a statement of doctrine taught in at least a majority of the sermons, followed by the quotes from each passage.
I've started calling this set of doctrines "The Sermon" given this high degree of repetition. It is also worth noting that many if not all of these doctrines are presented in some way in the temple.