Further update: I've now had the full article accepted by Think:

http://www.tryingtothink.org/wiki/How_Belief_Works

As I said, I'd had the first part accepted as a standalone article, and was intending to submit the remainder as a second standalone article. However, I found that I needed to include so much of the first article in the second, that I just submitted the full article, which will now be published instead of the first article (if that makes sense!).

I'd still appreciate any further feedback, although please post in the Google Groups forum on my site as I don't normally use this forum.