The only question I have is: why was Hawking's name the trigger? What about her involvement made Ben decide he had to kill Locke, or was he planning it from the beginning? In that case, why was it important that HE do it, rather than allowing Locke to?
Remember what Jacob/Christian said when John asked why he had to kill himself? "That's why they call it a sacrifice."
I think Ben knew that John was supposed to kill himself, and did all that he could to prevent it- up to and including performing the deed himself, so that Locke couldn't perform the selfless act of suicide for whatever purpose Ben and/or Richard had in mind. Same reason (IMO) Widmore wanted to keep Locke from killing himself (and likely would have had Abaddon kill Locke).
(Offhand, I'm guessing there is some kind of power in the sacrifice, and neither Ben nor Widmore have ever had the kind of level of belief and dedication to perform the sacrifice that would allow themselves to return to the island. Thus, both men decided instead to sacrifice Locke so that they could achieve the same- and both were doing their best to ensure that they- and not the other- were the ones to be best placed to take advantage.)
In fact, that's the only thing about this episode that really bugged me- that we see John, and he seems to have finally achieved some real level of growth; he is open about his relationship and feelings for Helen for the first time*; he accepts the wheelchair with only slight reluctance for the first time; he is unwilling to pull Walt out of his life and put him back on the island.
Then he goes and blows it all by chickening out of suicide and- far worse- once more believing Ben (who has tried to kill him before and has openly resented him from day one). Not that I'm saying suicide is in any way a brave act or anything, but in the context of the story that is developing on this show, and in the arc of Locke's character- it is the proper thing to do, and he once more shows a weakness as the leader he is supposed to be developing into since Season 1.
Otherwise- a great episode.
(*I am of a mind that either Widmore/Abaddon had Helen killed or else faked the tombstone in order that Locke wouldn't have any kind of change of heart about returning to the island. Abaddon is supposed to get Locke to where he is "supposed" to go, after all- so it wouldn't do to have their sacrificial lamb decide not to go anywhere.)
(As for Hawking's name that seemed to catch Ben by surprise- I assume he just didn't know that she was the key to returning people to the island for some reason. He clearly knew her from before Locke mentioned her, but I think maybe he just hadn't realized her link; he didn't even know of her connection to Faraday until recently either.)