purre: Your difficulty in talking to Khalid is most likely a result of sucking all your points from Charisma to put them elsewhere.
Kivan is, on all counts, an excellent character. His CON isn't great, but as a Warrior, he gets decent hitpoints anyway, so give him a good Bow and a good Spear or Halberd, and he'll be a great backup Tank for as long as your Rep. is good.
However. As far as combat goes, there's not a damn thing Kivan can do that Coran can't do better. Archery-wise, he'd put Kivan's ass in a sling six times before breakfast, and let's not forget that he's all the Thief you'll ever need if you train him right. Sure, his STR is only 14 compared to Kivan's 1

12), but just give Coran the Gauntlets of Ogre Power, and then sit back and watch that bad boy Backstab. Sure, his picture is ugly as sin. So? Give him a new one. Sure, you can't recruit him until you're in Chapter 4. So? If you know the game, you can blaze through Chapters 1-3 fast as lightning. Once, I entered the Bandit Camp when my PC (a Fighter) was only Level 1....although he was Level 3 by the time we left.
Coran. Coran Coran
Coran.