I't sounds to me like the pains you are experiencing with your shins & tight calves is normal adaptive stress pains. Although having never actually reviewed any of these "couch" to whatever distance training plans, I'm sure the approach to these training programs are very conservative. You should be slowly easing yourself into running, which I'm sure you are doing. Yes? Anytime you put a stress on the body that is not used to it, it cries out. I returned to running after taking 20 years off. For the first year (after resuming) I ran only 3 days a week. Could I have run more frequently? Sure. But in the three years of running this time, I've never missed 1 day of running because of pain or injury. In order to be a runner you have to run, but you can't run if your body is not adapting to the level of stress through proper recovery. Recovery is just as important the running itself.