I'm reserving my remarks on the Batman & Son arc for next issue's annotations where I really cut loose on it. The annotations this time are pretty rich in speculation to compensate for the lack of content up here at the top. So let's get to them.
Page 4: Perhaps a gaff by Dave Stewart, I think the Batmobile's fender should be black, its color upon completion in 676. David Uzumeri, in his annotations for the issue, proposes that the Batmobile is symbolic, which he's probably right about, and he even ties it to a theme of nature vs. nurture, which I hadn't considered.
I think actually the whole Batman/Batmobile connection is something Morrison, in his boundless ambition, really wanted to illuminate upon, but with all the ideas he juggles in this run, his reach simply exceeded his grasp on that point. Notice that Morrison titles the first chapter of his serialized novel "Building a Better Batmobile," which isn't a far cry from "Building a Better Batman," something Alfred set out to do in 655 after Batman's rogues were all jailed in the Missing Year and OYL. Here the Batmobile is incomplete, like the run which aspires to change Bruce Wayne's life. Next time we see it, it's red and black, the colors of Bruce's obsession. As it stands, the parallel doesn't stand out enough to be particularly noteworthy, but we'll forgive Morrison not developing it, because he really does have 10 trillion other things on his plate.
Page 11: I just love "You dishonor your sensei with the loss of composure!" It's the perfect way to coerce obedience from a martial artist.
Page 12: Morrison disinters another relic from Batman's past here with the Spook. The Spook once smuggled convicts out of Blackgate through a series of underground tunnels, as explained in Detective Comics 435. Like I said in the annotations for Batman 655, Morrison was lying when he said he would resurrect the O'Neil/Adams hairy-chested love god Batman. What he did instead, which was a better move anyway, was return Bruce Wayne to the Batman: Paranormal Investigator type comics from the Englehart/Rogers Len Wein era which showcased these sort of surreal stories where everything was always smothered in smoke and fog and rain and people were never really who they appeared to be. This story, Batman 657, only pays a superficial homage to that era with the Spook's brief appearance. On the whole, Batman & Son is a Golden Age story. But Morrison really does dig his hands into those Engleheart/Rogers stories with his creepy Third Man arc in 672-674 and much of RIP.
Page 13: "Suction cup and smoke bombs and electronic gimmicks..." The Spook really uses all these gimmicks in his crimes
Page 14: The second instance of beheading, the first was in the newspaper Gordon was reading in 655. Maybe Morrison is implying that Batman will "lose his head," as in going insane? Pretty thin though.
Page 16: The whole bloody key bit is unnecessarily opaque. Combining this scene with another in the next issue, I gather that Damian did not, in fact, read Alfred's fingerprints off the keypad, but instead, keeping with his prickish M.O., just jacked the key from him.
Page 20: Wow. Pointless really, but wow.