Courteth was a poorly-drawn character, and you're right that the Courteth/Ryalla relationship was bad.
I said above a few times: it isn't fair to judge this against something like Words of Radiance. Brandon knew perfectly well it wasn't a good novel, and has every intention of completely reworking it, the way he did with Way of Kings.
EDIT: Coming back to this months later ... Did I mention that "prime" is Latin for "first"? English descendants include primary and primal and primeval. And, Latin not being English, also principal.
That was weird. Apparently, even months later, this forum software won't let me reply to @Treamayne again without merging my two replies. Annoying.