I always figured some of those quests which repeated looking for precise items were all just cunning tests disguised as quests from members of some secret Thieves Guild. Ragrian sneaks down to the caves and throws the necklace into the slime herself nightly in order to find out which adventurers' pockets not to pick, Moraken really invented Storan and his ring via necromancy to test potential apprentices, etc... For the chieftain head hunts, savage tribes will always elect a new leader, so it's not too much of a stretch for them to be consistant. Then, for some items, I could see how one'd need a constant influx of them.
As Willowisp Essence and Goblin Ears are key ingrediants of various hooch, I suspect that Talon and Mage Dalton are secret partners in a brewing business, either that or chronic alcoholics.
Far as NPC quests go, we really need to get Talon and his Ilsarite healer woman hitched... maybe have Milara turn out to be a jealous ex-boyfriend wedding crasher or some such.
