"Anomymous. If you have your back on a door and you are on your toes and you bend your knees, your knees will be slightly in front of your body. Your body which is over your heel which in turn is over your toes. Read that last sentence carefully. Having found your true center and get the feel of your back moving up or down the door. Try to get into that position on three in the Waltz lowering on 3 (and) with your back as above. You are now on balance. There is no other point of balance whilst on your toes lowering."
This is all well and good while your heels are off the floor. But once your standing heel touches down, the lowering continues in the knee. That will project the knee forward into your partner if you keep the body stationary. As a result, you must not keep the body stationary. Instead, you must being to move it forward so that it stays nearly over the advancing knee. Your door analogy is still good, but now you must saw the door off and cary it forward with you, so that it can still do its job of keeping your back aligned even as the whole package moves forward.
"Foxtrot. Try the third step of the Feather and stop. Where is the center of balance now using your toe or heel as a point of reference just before lowering. "
From the point your feet pass into the third step onwards, you are accelerating which means that you are not in balance at all.
"None of us get high enough on our toes."
In actuality, the opposite is true. In foxtrot, most dancers get far, far too high for their quantity of movement.
"Most of us only get to the ball of the foot. That can hardly be called a toe can it.."
Except in waltz rise, that is all that is desirable. High rise is for abosrbing the movement to stop the body and close the feet. Moderate rise for steps that continue movement with either a temporary closure as in a chasse or a passing of the feet as in foxtrot.
And even in waltz, the appropriate amount of rise is just that which absorbs the movement, and no more.