The big thing it's missing right now to be called fully playable is a proper diplomacy module. With that in place a lot of the rest is a matter of taste whether certain features should or should not be in the game. And frankly there's some things in the game where the experience would be the same or even improved if they were cut out entirely (Smithing, children, etc) But a diplomacy model is non-negotiable. To many the entire point of the late game is diplomacy.