Well, I’m back up, it seems. The technical problems on the backend appear to have been due to some gummed-up WordPress plugins and an old version of PHP.
I’ll confess that I had begun to suspect that something darker was happening. My recent exclusion from Google search results (while Bing and DuckDuckGo results were unaffected) has got me looking over my shoulder a bit, I guess. (I’d like to think there’s an innocent explanation for that, too, but I don’t have one.)
Anyway, I’ll ask you all to let me know if you notice any problems henceforth — in particular, slow loading, or any reappearance of the caching issue that caused the comment-box to be pre-populated with the previous commenter’s information.
Thank you all for your patience, and I hope to get back to normal output shortly. It’s bracing to have the site working properly again.