Since you used "/etc/init.d/cups start" and it worked, you must be using cups1311 - just be sure you don't have the cups extension loaded at the same time.
I seem to remember the cupsd.conf in the cups1311 extension had been adjusted so that you didn't need to be root to perform cups admin tasks, but in case you do, you can use "sudo passwd" to set the root password.
I'm guessing you cannot edit /etc/cupsd.conf because either you did not try to edit it as root or because it is a symlink to /tmp/tcloop/cups1311/etc/cupsd.conf.
Is the first is the case, use "sudo vi" or "sudo beaver" or similar to edit the file, if the second is the case, you can delete the symlink in /etc, copy /tmp/tcloop/cups1311/etc/cupsd.conf to /etc and then use "sudi vi" or similar to edit it.