Re: 6 Directions
I think we're oversimplifying reeling silk a bit, but that's okay, it's common that different perspectives exist around the same core elements.
Cady, I like the sphere notion for neutral structure, but from a peng jin standpoint there may be a risk in losing the notion of the Qi of Earth whereby you're mentally manipulating the solidity of the ground through you (initially, then as you get better and more relaxed, you can do more with gravity as well) because in an initial practice, you don't usually have the connectivity to do much ground transmission without relying on bracing or structure.
I'm not going to presume that I know what's all being described by "spirals" and "spiraling power" but the windings of the feet through the frame certainly do play a part based on internal hand-foot connection, how much that connection has been conditioned and the relaxed skill in its use. I think there's some things left out when discussing silk-reeling with regard to dantian (tanden) and where sounds and the breath come into play both from a training/conditioning/skill and an application standpoint. Additionally, there are some body methods that help "close the circuit" so-to-speak when it comes to maintaining the full feeling when you're moving all parts together. Plus, the extraordinary amount of work/solo training needed to condition the right stuff (beyond rudimentary jin) in the body.
That being said, yeah six-directions and 6 harmonies (the internal harmonies for using qi and the external harmonies of how qi is expressed in a person's body) are not the same thing.