QuestHelper will show the status of your entire group on a quest. They update the tooltip when you mouse over a mob/corpse and show how many drops each of your group members still need.

I am not aware of any way to make collection of ground spawn items easier, personally I swap mains which switches my WoW windows as well. So I collect with my main till I have all I need then I swap mains to the 2nd character and collect till completed etc.