It teaches stability and balance. You have certainly provided a more in-depth perception with this discussion, but it makes perfect sense. My first foray into the arts was Shotokan. It may be wrong, but that is my experience. Now, if he pulls it up, I don't necessarily fall down.
More points equal less tools to use.
Well, the heels are close together relatively. Look down at how you are standing. Now draw a line from your left toes to your right toes. The larger angle 1 is tends to follow how much grappling a person has done. Now this doesn't mean only grapplers do this.