Regarding the lead up to Kaladin's Oath to protect even those he hates, I think the issue here was that he had given his word to both Moash and to Dalinar, and these oaths were contradictory. This was why Kaladin in particular had to progress--he had to resolve this conflict within himself. I think that another Windrunner could have stayed at the Second Ideal perfectly happily, without that internal conflict, and not have the same need to progress.
I actually wonder if Kaladin could have sworn a different Third Oath than he did, and killed Elhokar rather than protecting him, if he was in the right state of mind. After all, killing Elhokar was construed by Graves and crew as protecting Alethkar.
