Mike, interesting comment about the shoes not mattering if you run right. Sounds like a correct statement to me. Also agreed that the minimal-type shoes teach you in a hurry. In fact, I've heard of one Russian running coach who has people start barefoot on concrete, since nothing will make you learn faster. Sounds very Russian in a way familiar to all of us here, no?
I can comment from a mountaineering perspective. The less material you have under your foot, the less likely you are to twist an ankle. Imagine how hard it is for runway models to strut in high heels. Why would anybody try to do that while hopping around on boulders? In outdoor shops I always see city people buying stiff boots "for support", and the salesman unconsciously making a $400 sale. Then the same poor people have blisters a few miles down the trail. What I actually wear for mountaineering is low-profile trail runners. I throw out the insoles and have a shoe guy grind off the tread and glue on sticky climbing rubber. Not completely flat, but close. It helps to actually feel the texture of the rocks poking you in the foot so you don't slip. I can take a very small amount of barefoot sidewalk running at 200 lbs, and hope to build up to more.
Mike, both distance runners and sprinters run intervals, taking anywhere from 1-30 minutes rest between each one. The faster they run the longer they wait before starting the next one. In order to run faster one must run fast consistently.
LSD running is used to build and then maintain an endurance base. Hurricane Carter would run up to 20 miles through the woods before going to the gym where he would then jump rope for 40 minutes (which is equal to 120 minutes of running) before taping his hands and putting on the gloves. Boxers and soldiers both run. In the ring the fittest fighter, not the strongest, usually wins.