I like this story a lot, but you had a huge mistake in your timeline. Harry didn't date Cho and ditch her to be with Hermione until 5th year. She was (and presumably still is, as he is still alive) with Cedric at the end of GOF.
I agree that Hermione had the inside track up til the end of OotP, though, until something happened and she lost 90 IQ points and developed an unnatural desire for an emotionally abusive relationship with a ginger.