I dont recognize any of theese: Barlot at Pissing, More Cowl Tasks, Of Elves and Artifacts, Selim Sivad, The Subdual, Den of Nightly Brawls.
Kangaxx underground? Is that some continue of Kangaxx quest?
The I will look for "the mysterious wizard" in Government District next time im there.. 
"Barlot at Pissing" is small encounter at Umar Hills.
For "More Cowl Tasks" you need to do Planar Sphere quest.
For "Of Elves and Artifacts" you need mage or sorcerer in your party. Then go to front of Temple of Helm at Bridge.
"Selim Sivad" is encounter after you have finished Academy of Kuldin but he/she hasn't appear in my game ever.
"The Subdual" is dragon encounter at Sunset Mountains. You get map from Pirate at City Gates.
"Kangaxx Underground" is probably part CtB class quests but you can go there, loot and kill everything. Probably don't have anything do with Kangaxx quest.