At this point, I'm trying to assess what amount of work it's going to take to get into one of the "big 4"-type companies. I also need some way to feel like I'm improving.
1.5: Interviewing is like dating. At the end of the day, it's all about a mutual compatibility among you and the people you work with.
2: Interviews aren't things you study for. When I interview candidates, I'm trying to figure out if they can learn and if they understand core concepts that come with experience.
I must say this: I can tell when someone studies for my interview. They get all the questions "right," so then I start twisting the questions and the candidate starts acting like "you said this wouldn't be on the test." Those candidates are rejected.
In an interview, I can always take some code on the board, make up a funny situation that you didn't study for, and see how you handle it. If all you do is study interview questions from a book, these questions will tank you.
I've had two situations where a candidate who studied my interview made it past. In one case, the candidate was fired after a few months because he was too focused on goals that weren't our business's goals; and because the quality of his work sucked. In the other case... Well, let's just say that upper management is well aware of the problem.
Personally, I don't find it useful to perform a rote rehearsal of the material. I'd much rather be able to intuitively understand it because I hope it will help me in areas other than interviewing.