Terithuir

First off, I was wondering if anyone could tell me where Zephir the shadow thief is. I recall meeting someone that looked like a thief and was named Zephir but it was before I started the quest to find the Dangerous Criminals.

Secondly, I would like to know where I start the Disappearing Merchants quest. I have talked to Coprith but I havent a clue whats next.

Also, I was wondering where Lord Signax's Commander Chief or w/e is, because it seems I have to talk to him before I am able to go to the Tomb. If not then there is a bug that doesnt let me go to the tomb while at the world map, I can click it but nothing happens.

Final question, is there a Good Aligned pure mage? I don't like using the evil wild mage, even though Imoen is soooo much better due to the ability to cast 8th lvl spells right off the bat, while the wild mage is only casting 6th lvl spells.

Thanks for any help, not very far in but so far the mod seems good with some cool npcs(although I don't like how Derek apparently killed Valygar by levitating a boulder to drop onto him...considering Derek's alignment is Lawful Neutral)