Also check your ignition switch!! THAT would be my first check as a mechanic. What you described: "I have to turn the key quickly several times then hold the key in for about 8 seconds to start." Sounds like a faulty electrical connection in the switch, hence the "die while I'm driving" scenario.

Think about your service for a moment.They replaced the crank sensor, and it did not help, which means that your crank angle sensor was OK and they MIS-DIAGNOSED IT! In fact, I'd say they just took a shot in the dark just to be able to bill out a job. Why else would you see NO improvement??

To qualify all this info I'm laying on you here, I should mention that it is coming from a lot of experience over the years working in various shops as a mechanic. I'm a good one. I'm honest and I use a more logical approach to diagnosis.

Hope this helps... good luck.