I attended an Expo recently where the great Ann Audain spoke. She mentioned that she had run for 22 years professionally with no injuries. During the Q&A, I asked her how she managed that. She gave several reasons, one of which was that she wore minimalist shoes. Her advice was to find the lightest flat you can and train and race in that.
She probably told the story about being born with club feet and that running was part of her rehabilitation from numerous surgeries. I think her story sort of kills the idea that you need to be "biomechanically perfect" to run in racing shoes full time. She told me that she lover her Nike Columbias and that when Nike put air in their shoes they were "too soft" so she got them to keep making the Columbias for her.