Roy,
I like a lot of what Snowden says, particularly his thoughts on knowledge management, but my experience is slightly different. I am more in the camp of Clancy or Shaw who see compexity and emergence as forever iterative simply because the act of change creates each time a different platform from which to launch further change.
As for your comments about 'heuticulture' - I had to laugh. Although I suspect that horticulture still requires a certain 'hands on' approach from the master gardener. Had you thought of the Lamarkian biology?
I am also of two minds with the 'creation' and 'shutting down' of design. Isn't it the aim of emergent learning that learning never starts - nor stops? That learning is because it is? (How Kantian of me.) I don't know, but it sounds like something that is perhaps better discussed over a good red wine :-)
Phil