for the Raj robbery to take place you need to talk to Vishka first (solve the conflict) then talk to Tula and then do the sex scene with Raj (robbery takes place during that). Collecting the items is easy, Raniz-Kujins for the spices, Nami for resin, Katai will eventually give you the blood and the ice you will hike....then make sure its night time and head over to the horse's camp (forget the name) and make the potion