Re: Moving with your center
FWIW, I agree that Tohei's four basic priciples can lead to some confusion. Heck, I've seen it and explained around it myself, but there are other things in what he taught that provide clarification for some of those principles. Relax completely goes hand in hand with orenate (unbendable arm). It's often seen as one of his ki tests, but it is also a foundational, physical thing that should be stressed and focused on in EVERYTHING you do. You can't have one without the other. If someone spends some time resolving those two concepts they can get a pretty good idea of what it means to be strong and connected, but also relaxed and soft.