I thought the depiction of the Occupy Wall Street was a bit oblivious. It wasn't negative, per se, but it was definitely unsophisticated. Even the name--"Occupy Wall Street" is a pun on the idea of just occupying physical space vs. a military occupation. "Take Over Wall Street" is far more aggressive.
I had the same problem with the fake name -- it was an unfortunate choice that played right into the worst fears and stereotypes about the movement. I guess they had to use a phony name, because the story entailed an organizer of the movement being partly responsible for the crime, so that would've been libelous if they'd used the real name. But I wish they'd come up with a better synonym. How about "Monopolize Wall Street"?
The flashback approach was an interesting departure for this show, but it made some of the clues a little too easy to spot. At first, I thought the drummer would turn out to be the bomber, given that he was noticeably present in two scenes yet not called attention to at the time. Turns out he was just a witness. But I did notice the guy who bumped into Tim Guinee in his flashback and knew he'd be the bomber -- although I thought he was the guy who'd lifted Guinee's phone, and it turned out that was somebody else. But I did see the stolen-phone bit coming a mile away. (And what a creepy bit of Person of Interest
sleuthing they did with the cell-phone tracking. Although I'm not sure real-life cell-phone GPS is precise down to that resolution.) And I started suspecting the reporter a few minutes before the reveal.
As for the romance stuff, I'm not really interested in that. I've long felt Castle & Beckett work best as friends and professional partners. For me, the most interesting character thread here was Alexis dealing with the tragedy and telling Castle that this ME job is the first time she's felt she was doing something genuinely important. Which is probably a way of setting her up in that job on a continuing basis, which strikes me as a little contrived, but is fine with me if it gets her more screen time.