1)
a. Slaying Saeros and his flight from Doriath
b. Allowing the evil deeds of the Gaurwaith
c. Refusal to return to Doriath when found by Beleg
d. The death of Beleg
e. Overruling Orodreth and Gwindor in Nargothrond and abandoning secrecy
f. Building the bridge, Battle of Tumhalad
g. Abandoning Finduilas to seek his kin
h. Marriage to Nienor
i. Killing Brandir
2)
a. Morgoth's curse
b. Parting from Morwen
c. Ceasing of tidings from Morwen
d. Death of Finduilas
e. Death of Beleg
f. The sack of Nargothrond
g. Death of Nienor
h. Nienor's true identity
3) His pride in Nargothrond, which caused him to urge the Elves to open war, overruling Orodreth and Gwindor, building the bridge that eventually allowed the sack of Nargothrond.
4) The revelation of Nienor's true identity and her death, which drove Turin to despair after his victory against Glaurung.
5)
Similarities: Courage, loyalty
Differences: Turin was stubborn and refused to return to Doriath
6)
a. Neithan, the Wronged; Gaurwaith
b. Mormegil, the Black Sword; Nargothrond
c. Turambar, Master of Doom; Brethil
He would hide from the doom of Morgoth, not revealing his right name.