A few things to note: it's probably less that Korthox needs a buff and more that Slough and co. would need a nerf. Remember that you're comparing a champ designed to use a weapon to a champ designed not to: Slough's damage is high to compensate for that. If you compare Korthox's damage to, say, Tandis, the comparison is much more sane (2 phys, 3 cold vs. 8 phys.) Korthox also has really high base defense, more than double most other champions. If Slough can suddenly use a
Grakor456
Ice Lords, definitely. I have a particular affection for characters that are brutish/monstrous looking, but have an intelligent or mystical side. Ice Lords just have that primitive, but honorable and intelligent, brute kind of feel that I just dig. Notable second goes to the Keepers of the Flame. I just love their dialogue, they definitely give off the vibe of a faction that knows a lot more than they are willing (or able?) to convey.
More RPG leaning is my vote, since I think that focuses more to SKs strengths and differentiates it from other games. I'd like to see more champions, more story and quests, and more interactions with rival factions. Perhaps quests from allied rivals for the ability to train their units and create new items, and quests to cause enemy rivals to betray the Sorcerer King?