How can you determine the "hub" nodes in a small-world graph especially when the degree distribution is fairly symmetric? I imagine what constitutes a hub or not is fairly arbitrary, or is there some criterion?
These metrics are called 'centralities' in network theory. The one most likely to be useful to you is betweenness centrality. The betweenness centrality of a node is the proportion of all shortest path lengths in the graph that go through that node.