Anyway, you should always disable EVERY daemon until you know exactly what it does and how to configure.
Now, there are two ways to go: a) If you don't install a daemon that you don't know it won't be enabled by default/yast. It's much better to read the man page first -and install a daemon if it is needed. b) If you choose a standard installation with various daemons check your /etc/inetd.conf, disable all unknown daemons (that are enabled by yast) and edit your configuration file (in that you can disable those daemons).
No problem to do this for somebody who knows Linux well. But even userers who are using Linux now for more than 2 years do not know a lot about the interns and the relatet security-risks. 99% of them do not know "Know Your Enemy" and 99% of them use some "Standard-Installation". And they aren´t that able to edit conf and rc scripts. (BTW: for nscd there seems to be no manpage/documentation. And I do not remember beeing asked at installation if I want to install nscd or not.) Hartmut