I figured out that I'm going to have to write a FreeBSD-type startup script to replace bro.rc, so that problem is "solved". I also figured out the syntax for the local.site.bro file and some fiddling around and reading.
Now I have another question - how do you daemonize bro? bro -h doesn't show a daemon switch (normally -D), and when I run it, even without the debug switch, it does not daemonize. Obviously, from the cmdline I can use &, but that is not available from a startup script. What's the normal convention?
Now I have another question - how do you daemonize bro?
There's no mechanism beyond '&' from a shell. I'm confused by your
statement that this isn't available from a startup script, since we
routinely run shell scripts (that then background things) on our
FreeBSD systems upon startup.