I fixed the WordPress issues I was seeing by simply deleting the rewrite_rules from the database, just wiped ’em out. WP generated a new set and all seems to be well now.
So, to be clear, it had nothing to do with apache server configuration, nothing to do with php, nothing to do with FreeBSD or OS X, and everything to do with WordPress and its self-appointed experts who couldn’t pour piss out of a boot if the instructions were written on the heel.
Color me annoyed.