Upon finishing reading Words of Radiance, I actually thought of a slightly different path for Adolin regarding the Radiants.
My theory is that Kaladin might end up giving the honorblade to Adolin, making him a sort-of windrunner, which leads to trouble as Adolin makes mistakes since he doesn't embody all the ideals of Windrunners (or his murder of Sadeas coming to light obviously) leading to Adolin's path taking a turn. After reading this thread and your very interesting theories, I'm thinking it might lead to Adolin discovering his bond with a spren and his true order or him joining one of the other groups.
My bullet points as to why this might happen:
-Windrunners were known to fight in groups, thus Kaladin would ideally want more members. Bridge four might fill this gap tho.
-Adolin and Kaladin already fought together both against the assassin and to a lesser extent in the dueling arena.
-Through the book Kaladin started to view Adolin more and more as a good man, perhaps seeing in him certain aspects worthy of a Radiant as evidenced by his remark at one point how it wouldn't be so bad if Adolin did turn out to be one. Kaladin just doesn't know of the latest developments.
-Kaladin has a history of making somewhat bad decisions when it comes to giving out shards.
All this is really just my initial reaction upon reading the book, and of course might have a bunch of holes in it. But I really do like the idea of Adolin becoming a Radiant, and I don't see it happening without some sort of big issue that attracts the bond with the spren and I think my idea might still fit.
