/usr/local/bin/spamd -D -x -q -d -m 16 -r /var/run/spamd.pid -i 127.0.0.1 -A 127.0.0.1 -u spamd -s mail.crit
I can't answer your questions, but that -m 16 has me worried. At around 40-60 megs per child, that is using up a LOT of ram. Unless you have a few gigs spare on this machine I'd stick with the default of 5 children until you have things up and running moderately well, then experiment with more if necessary.
Loren