New cups 1.4.x introduces many new features. Due to config syntax changes, please start with a new cupsd.conf file. You can create one based on /etc/cups/cupsd.conf.default.
USB-Printers: In order to get usb printers working, you need to disable usblp module in your rc.conf file. Please blacklist usblp module in your /etc/rc.conf file, eg: MODULES=(!usblp)