I have been following this thread eagerly, hoping that smarter minds than mine will find a solution...but I had a few thoughts.
1) The people who are working on the diagram in the book are able to tell that one of the entries is a list of dates. I know that people on the forum have speculated that these are the dates of highstorms, but given the context, I slightly disagree. Here is my reasoning. These characters are already very familiar with highstorms and the calculations to predict their occurances, but "(This appears to be a sequence of dates, but their relevance is as yet unknown)". This tells me that they do not correspond with currently known lists of highstorm dates. My theory is that they may coincide with dates that the Everstorm will occur and cause parshmen to change into the new storm form, or dates that the Everstorm encounters the Highstorms as the two systems circle the globe.
2) Many of the references in the epigraphs mention "kingship" or "king". I believe that this may link something in the epigraphs to either the Brandon Sanderson novel WoK or the in-story Way of Kings that was read by Dalinar in the first book.
3) Floorboard Paragraph 2, sequence 1 references making a Truthless and using him as a weapon, Paragraph 6 expounds on this by saying that the danger in using a weapon like a Truthless is the possible encouragement of those exploring the Nahel bond to say more words and become closer to becoming a Radiant.
4) Floorboard Paragraph 2, sequence 2 talks about a Parshendi who will gain their power and form a bridge. After reading the Listener epigraphs, it is clear that the Parshendi COULD bond with a spren, but that the spren prefer men. If a Parshendi were to bond a spren (say Shen aka Rlain for example) then that could form a bridge between the two powers of Honor and Odium. Hence the desire to have the Alethi wipe them all out.
5) I don't know if this is helpful or not, but "They will come you cannot stop their oaths look for those who survive when they should not that pattern will be your clue - From the Diagram, Coda of the Northwest Bottom Corner: paragraph 3"
A "coda" is something that ends and completes something else. It is the only passage that is identified as a coda.
6) does this sequence strike anyone else as odd? "SetoffObviousRealizationlikeapricity"
Anyway...that's all I've got...hope some of these ideas spark something for the rest of you!