What a great scenario for keeping Snape alive and having Harry run into him.
I thought your take on Teddy and James's troubles was so intriguing. I've always seen Teddy Lupin portrayed as either slightly troubled or lonely, but not on the dark side of the spectrum, so that was really compelling for me. I feel like I want to re-read those sections to consider more how he involved James and the other students, and think about some of those more bleak possibilities for the character.
Harry is just so eager and happy and elated after his night with Severus -- loved the tickling and his ready acknowledgment that he was totally lying when he first claimed he didn't want anything serious.
Oh, and the idea of Snape being more attracted to helping James or even to Harry himself because of their failings and need for redemption to whatever degree really worked for me. Cool story!