Have I ever mentioned that I love your creativity with spells? I would love to see that diagnostic spell in action.
And this sounds very promising; that's a different Harry from the ones who become Healer or Auror and have no real problems from the outside. The greatest difference is Draco; he's usually striking and gasp-moment-why-did-I-gasp-it's-Malfoy or interesting in other ways; I look forward to how that will work out!