"No, No. He Did Not"
L did not sit like that for the heightened thinking ability.
He sat like that because he was utterly scared.
L did not bite his thumb because he was hungry, or it helped him focus.
He bit it because he was so very, very nervous.
L did not slouch because he saw it comfortable.
He slouched because even two inches closer to the ground felt safer.
L did not handcuff Raito to observe him.
He did it because he wanted, just for once, to feel close to someone, anyone.
L did not hate Raito because he was Kira.
He hated him for lying every time he said 'I love you'.
L did not die.
He simply lost the game.