My further suggestions:
If you are getting shin and foot problems in Vibrams, running what you believe to be POSE, I'd highly suggest you spend the $$ to do a session or three with a POSE coach to make sure you are doing it right. As I understand and have experienced it, the shins are hardly involved (in terms of being stressed or fatigued) in POSE, so if you are having problems, it is either from lack of adaptation to the new style, or the possibility you are doing it incorrectly.
The chest pain could have been from the cold air and not warming up, as well as the caffeine.
Sounds like the "perfect storm" for a crappy test result. I'd say learn from it, then kick a$$ the next time.