This is what I'm hoping for Kaladin as well. I don't like how Kaladin has left everything of his old life behind. Though to be fair, he didn't leave them behind so much as they were taken from him. Still, I'd like it if someone came back. Other than Amaram that is, hatred for lighteyes is more or less constant for Kaladin so he's not bringing anything new.
And yeah, I didn't get the sense Tarah was a random bit of trivia from Kaladin's time in the army. I can totally see Brandon foreshadowing a romantic interest for Kaladin.