In this summary, we leap from a father being told how to save his daughter to him being a terrorist. I would hope that the film fleshes out this summary, though I am doubtful. My experience with JJ Abrams films is that he doesn't have a deep understanding of human psychology.
I really can't think of many things I'd less like to see in this movie than a five-minute sequence showing the gradual conversion of some random guy into a minor henchman who dies shortly after.
So it seems to me Abrams understands human psychology just fine. It's all in how you look at it.
Same here. Some parts of a story can be left to the imagination of the movie-goer. Clarke was an obviously desparte person who made a deal with the devil. If he doesn't follow through, the consequences are certainly terrible for his entire family. That's explanation enough for me.
Though, you still gotta wonder why that's the only method Harrison could apparently use to achieve his purpose.
Perhaps within story, getting Clarke to do it is supposed to display the extremely persuasive powers Harrison is said to have.