Welp, I gave up and returned to my original CMS, Textpattern. It only took me a few hours to rebuild the site, and I got it up and running without any fuss. As the saying goes, “you don’t know what you’ve got until it’s gone,” and I never appreciated how sensible Textpattern’s implementations of certain features were until I tried to do the same thing in WP. I’ll have to make the switch to WP someday, but I’m going to cling to Textpattern for as long as I can.
I spent several hours trying different options to no avail, so I moved WP to the root using the multi-site move instructions. However, now nothing works (Error establishing a database connection) and I suspect it’s because I didn’t move over WP’s .htaccess file, which I knew would interfere with my existing .htaccess settings.
How can I safely integrate WP’s .htaccess settings with my existing ones so that all requests to example1.com continue to point to a subdirectory EXCEPT for requests related to WP? So a request to example1.com/wp-admin should show wordpress, as should a request for one of its multi-sites like example1.com/foo.