#5 is in the library with Tyria and Falaen. Go to the West Wing, then go left. Have Tyria lose to the fire elemental by only casting the vines spell.
#8 is on the hunt with Duah and Mael. When Mael tells you about his backstory, ask how he got his title. Then when Duah starts mocking him, choose to say nothing, then let their conversation play out.
37-39 are endings with the boys. 36 should be an ending with one of the girls, if my count through the gallery was correct.