I would assume only the Martial devotion to the Rahls as well as the Mord-sith, would be included.
Mord-sith would probably be assasin UU's and capture units as slaves (perhaps with a small chance of capturing the pure unit, aka through command promotions) Mord Sith would probably have better sentry, from the geographical and troop position knowledge gained through torture.
I had no Idea there was already a television series xD ... is it too late to watch it? I only read the first 9 books.
// The Devotion ara was linked to how pure the blood of a D'haran was. Pure blood was generally shown through blond hair and blue eyes, and all Mord-Sith share this quality, as well as having skin tight red-leather, so that the blood from their torture victims does not ruin their look. The Mord-Sith are also all-female, so for now could probably use a re-colored courtisan unit-art (perhaps red around the chest and legs, to represent the leather)
In other aspects, the D'harans are very Bannor like, usually prefering to wear black armor, being highly trained and organized. Essentially, the D'harans are the best fighters in the world (at least melee fighters, which you emphasized in the traits)
As to the civ hero, I think each leader should have Himself as a leader. Richard Rahl would be a Ranger with the sword of truth, which gives +5 first strikes and the blur, haste, and dance of blades abilities. While Lord Rahl (the Father) would be an archmage riding upon a fire drake. Probably 3 movement, 6 str/10 def, potency, and chanelling I-III, as well as having the art of a black-robed archmage riding atop a small red Wyvern.
and by far, the Rahls would definitely have all units start out with the loyalty promotion. Or at least, all units of conventional warfare. Those that may be mercenaries, or of highly diluted blood, may not start with it. Only way I can see of implementing in game would be all melee, archery, and mounted would start with loyalty, while arcane, recon and disciples, perhaps not
EXCEPT the Mord Sith. (Mord Sith would have to have loyalty promo to be at all correct) In fact, due to the Mord-Sith's knowledge of human physiology, they should probably be given not only loyalty, but also medic I. Their extreme devotion would probably also warrant free courage and valor promotion, but to be the only units with this honor.
In all probability, the Mord Sith would probably cause fear among their living enemies. Only those that have not heard of the Mord Sith do not fear them.
//and for something completely different, I vote for the burning Banner picture of Brigit