To be fair, we also (to my knowledge) haven't had any POV's from Elkohar, nor has he had as much "screen time" as the other main characters in character development scenes. So while we get to see Kaladin, Shallan, and Dalinar go through trying situations both from outside and inside their heads, all we get is a relatively minor slice of Elkohar solely from others point of view. Furthermore, most of these characters are ones which have their own prejudices towards him: Dalinar's views about Elkohar are colored by his comparison to Gavilar, Kaladin's by his hatred of lighteyes, etc. So I don't think its necessarily fair to say that Elkohar is completely without talent, simply because we haven't really been given a chance to see him in a situation where he might be able to display a talent in a way that would be remarked on by another character.
Re: Elkohar and his knowledge of Szeth. During the fight in Ch. 33, Elokohar leaves with Renarin and the guards right after Szeth shows up. 3.5 pages go by (in the hardback) before Szeth reveals he is there for Dalinar. When Kaladin shows up post-fall in the next chapter, this happens:
So Elkohar has no idea that Szeth isn't after him, and its somewhat unfair to hold his mistake against him, given everything else that others have said already.
(Also, hooray for first "substantive" post! Been lurking here for a while now!)