DebetEsse, I like your list.
One thing I'm looking forward to, ever since the early books, is to have a scene in which Harry has to trust Snape. I'm hoping for that need to choose, whether to trust or not. Not even necessarily the result (even though I'm firmly in the opinion that if Dumbledore trusts somebody, then I trust them, as well), just the actual need to choose and trust.
So much of the books come down to those two things, choice and trust. Trust of a character's right choices. James trusted Sirius. The he wanted to show trust in Peter Pettigrew, and made him his Secret Keeper, showing him the deepest faith a friend can show, trying to make him feel as welcome and loved as possible, appealing to the best parts of him. Just like Dumbledore has been doing all along. And it failed. It was that same trust that threw James, Lily and Harry straight into Voldemort's wand.
In a strange sense, though, it was that trust who provided the chain of events that ended with Voldemort's curse being reflected upon him and his loss of power. And now, Dumbledore's ongoing trust of Snape, who wasn't just an untrustworthy friend, but also proved himself at least once as a member of the other side, by joining the Death Eaters, that trust seemed to result in Dumbledore's own death. Another failure. Another choice of betrayal.
From, IIRC, "Chamber of Secrets", I thought that one of the final confrontations in the end of the series will be Harry forced to trust Snape, without Dumbledore to lean on, to reassure him that this is the right way, to lead him. Plain and naked trust, either to give or not to. In "Half Blood Prince" while, as always, completely suspecting Snape himself, Harry trusted the Half Blood Prince's book wholeheartedly, without a second's hesitation (in fact it was Hermione, who follows Dumbledore in his trust of Snape, who mistrusted the Prince). He did go along with Snape, even without knowing it. And now what? Will he trust Snape? Will he trust Draco? Will he be right in doing so? Was Dumbledore? James wasn't - will Harry follow his father, or choose his own path, and in what ways?
And that's why I love that the whole question of Snape Good Or Evil could go either way, I think, why I like that complex structure that is playing in my head, the mirror images and reflections and twisted ones and then again. The very fact that it could go either way in a believable way that can be argued about. Even without any connections with the actual results and future events. Because now it's all up to the characters' choices. To looking at the situation and who they want to be and what they want to do with where they are and what they have, and that's what defines them. Not what already happened, but what they choose to happen next.