I don't like love triangles, and I don't like this one. I want Adolin, and I think it makes more sense.
The whole triangle thing was just thrown in there, and unlike the poster above, it was not done smoothly or subtly. The big thing is that Sanderson is normally really good at stuff like this, so... IDK. Could it happen? Sure, but I think it would be a mistake to push this way more then just skimming the surface. It is not needed and would distract form the plot.
And could someone please tell me these hints BS throws out about their personalities meshing so well? Shallan is a sheltered wealthy girl who grew up away from much of society while Kal grew up in the middle of pain and suffering. While Kal has watch those he cared for die/suffer due to no fault of his own, Shallan has ended up having to kill members of her family/some that she cared for and trusted, they are both broken, but not similarly or comparably. Kal does not try to hide his disdain for society, and is moody/withdrawn while Shallan is outwardly friendly and 'proper,' but hides her true self behind this well-constructed lie. Yes, is some ways they are opposites, but I do not see then really falling for each other as more then just a crush/ romantic excursion. I could see them starting something, but eventually falling apart and Shallan going back to Adalin.
As for the Kal/Jasnah stuff, I don't really see it happening, but I think the big thing is that they would bond over their shared dislike of everyone else. Seems weak, but it could happen I guess?
Edit: I'm tired and can't think, so I am adding to this.
Also, look at what drove the other girlfriends from Adalin: jealousy and that whole 'walk' around camp searching for answers on the king's assassination. Shallan fits into those well, she is a very big player in this whole thing, and wants to work, not take meaningless 'walks' around camp in her chariot. She is independent and does not seem like the jealous type (didn't Adolin mention that was stuff he wanted in a long-term girlfriend?).
Furthermore, if Shallan leaves Adalin for Kal, I would be scared for Adolin as a character. Any relationship between Adalin and Kal would be shattered and I could see it as a point for Adalin to 'go mad'/turn evil over the slight. Maybe this is what BS wants, and if so it might just be want we see, but I don't really see that happening.
As for the stuff in the chasm, I chalk it up to the fact that both obviously have feelings for each other, and they were stuck in a freakin' chasm thinking they might very well die soon. It would be incredibly awkward that they just sit there not talking, and so they talked. Thing is that they really don't have much in common other then being 'broken,' Shallan being the sheltered girl living in near-isolation and Kal being the ex-slave who has been to hell and back, and who loaths lighteyes.
