Re: torifune and IS
In my experience it helps to do the exercise with a partner. Your partner stands in front of you, feet side by side, holding your wrists. You do torifune and try to keep your partner moving while maintaining your own balance and posture. Proper distance is very important.
When you do the exercise like this you will feel how to move your center and remain connected to your partner. After that when you do the exercise solo its 'content' has become much more valuable.
Also I think the exercise is originally Shinto....but I am not sure.