leather and bones can be used for crafting .. but i wouldnt do crafting, since its most of the times cheaper to just buy it in the auction house
tau horn -> youll need it again if you want to do a grappler classchange
(fighter class)
the lugaru claws are needed for 2 or 3 of the lvl 5-7 quests too
(you need around 20 for it) and its always handy to supply your characters with them
(1st you have 2 free questslots then and 2nd you lvl up faster
)