I agree that the connections and flows are where most of the meaning is conveyed. The connections are critically important.
I also believe that it is important to consider nodes and links separately, and that, especially when it comes to learning a language, the nodes must necessarily come first.
Example: "Brick" is a node; a term that makes complete sense in and of itself. A picture of a brick can stand for or represent the object as much as a word can. But a word like "throw" -- which I would consider a connection -- for example, has little meaning without the surrounding nodes: the "brick" and the "boy" who throws it.
I have come to the belief that when you communicate visually, the nodes are the building blocks we use to represent reality and ideas, and the connections are the ways you construct them ointo meaning.
This may sound super-simplistic, but people have become ingrained in the habit of communicating in a linear, time-oriented way, because with written and spoken language that is the only option. Visual language opens a door to communicating complex relationships between many nodes in a single frame.
The learning barriers to communicating this way are staggering. People quickly become overwhelmed and shut down. In my experience they want a simple linear path, at least to start with.
Somehow I think that PowerPoint holds a key to this. There is a broad user base out there who is already communicating visually. Many are using PowerPoint already to convey complex, nonlinear ideas.