I enjoyed this a lot. The wizarding afterlife isn’t exactly fair, but I stopped worrying about it as the story grew on me. It was very dreamlike and I liked picturing them surrounded by teddy bears and flowers, counting chocolate frogs. A very unusual way to get them together and it worked! This was one of my favourite bits:
Snape's face flushes furiously at the sight of Harry holding out twelve Earwiggy Flowers toward him. But he doesn't slam the door on Harry, and better yet, takes the flowers and levitates them into a vase-shaped container that he insists is a potions container, absolutely not for flowers under any other circumstances.
Harry’s encounter with the bookkeeper was by turns humorous and touching. I loved seeing him realize that all his answers included Severus.