Concerning Joker's lack of reaction over Batman's death, there is his delusional insanity to consider. There was one comic where it suggested that Joker believes he's already killed Batman a few times, but that there have been replacements. If so, the current situation would be just "Been there, done that" to him. Either that, or he'll convince himself Dick was always the real Batman.
That's the fun part of such an insane villain as the Joker: you can explain a lot with just saying "Well, he's frickin' nuts."