Are you trying to resemble a what actually happened from the accounts? Something like this may exist although I am not aware of it which indicates that it is probably not up to date as the Navani prologue is fairly recent. I agree that a lot was going on. We do discuss the Navani prologue here but that is all I know of.
https://www.17thshard.com/forum/forum/19-stormlight-archive/
Brandon is saying that people from other shardworlds have innate investiture the quantity of which is not changed if they gain or loose breath from a nalthian.
You missed one method and I am afraid that it is the method used in this case. God literally decided that a planet there would be cool so they put it there(as above WoBs demonstrate).
That was a lie. Rock admitted that he was lying to bridge four when recounting his history.
That is a fallacy of analogy. We don't really know what spren look for. Them saying that they look for broken people means at least in my opinion that they look for people with a great capacity for growth.
That does not explain his wife's objection to that statement.
Rock has "special blessings" according to his interlude in OB. They probably relate to his singer blood and potentially relate to him swimming in one of the horneater pools.
Harmony changed the Koloss to make them true breeding when he ascended. Before they could not breed. Now (from coppermind)
Inquisitors could always reproduce
and Brandon has gone back and forth on weather Kandra can breed with humans(they can't make more kandra with each other).
So I actually recommend you read all the interludes as basically short stories(that is kind of what they are). Additionally read Edgedancer(you have not told her the plot and it is not nearly as much of a commitment). My favorite scenes that have not been mentioned.
Kaladin and Adolin becoming friends after getting out of prision.
All of Hoid.
I am a stick!
Recruiting the deserters
Tyn and Shallan's scenes(am I the only one that sees the two of them as a thing? Tyn is defo Shallan's type).
Skim at least a few of Kaladin's struggles and then read his how he decides to help Elhokar.
Honestly though maybe just tell her what the chapter is about and then either summarize it for her or read it depending on what she wants? Coppermind has descriptions for all of them.
Savantism is kind of like the spiritual form of addiction. If you use something too much your body and soul become dependent on it. It is possible with all forms of magic.
It could be just that he did not want to show Rlain glowing to avoid getting fan hopes up. It could also be that Rlain's form would give us an accurate idea of where/when he was allowing us some kind of inside knowledge. If he is in dullform for some reason that could give something away. Perhaps he gains an honor version of a form of power? Perhaps he goes undercover in an evil form of power. I don't see why they could not release something with him in his old warform but maybe he has to change form in book to do something important and that is how we will see him in the future(the way we see Kaladin as the glowing shardspear and bridge four as his squires even though many of them have moved on and Kaladin was a slave for all of book one)?
Short answer is basically nothing. This is the from the coppermind.
it can be found here https://coppermind.net/wiki/Dawnshard
Oh lots. I will put up a few threads. Spoiler for length.