Speaking from experience on the injury front, I can only re-emphasize the CHILL term. Unless you are Michael Wardian, you will break from the running addiction. I have seen the best runners in the area die off one by one due to injury. They peak in their late 20s and then, boom, something happens, and by their early 30's they are a mere shadow of their former selves. There is always the exception such as Hage, Moeser, Rolly, etc. but these are by far, the few and lucky.
Jake and Reaves and others are running great. However, some are putting in miles similar to what the pros do. Unless I am missing something, very few of you if any really take time to do the body maintenance thing such as go to massages and Yoga and all the things you might think are lame or not important, you do not have time to do, etc.
All of the pros who put in the megga miles and train hard do lots of the maintenance to keep the blood flowing and the muscles limber.
Think of your bodies as being really expensive cars(the best). They need to be oiled, tuned and pampered to run smoothly.