I agree 100% I like the ideas Vicious, but the Joker is
never a pawn. He's too smart, and secondly, showing the Joker's origin would be a huge,
huge,
HUGE mistake.
Part of the reason the Joker was such an amazing villain in TDK is because we
didn't see his origin. Part of what made him compelling was the fact that he told multiple stories about how he got his scars. Actually wondering what happened to him, and theorizing about who and what he was before he had the scars, and all the debate that arises around it (was he always crazy? Did he scar himself? Did the scars drive him crazy?) is part of what makes Nolan's Joker such a great villain. One of the best movie villains of all-time in my opinion.
Actually showing what happened to him will take away that aspect, and also, it will never live up to everyone's individual idea of what
could have happened.
In short, you would be destroying part of what made a great villain great, in order to build up the other villain.
However, I don't want to sound like I'm bashing you. I really like all the other ideas, it's good stuff