Hello, kpersonalizer is a simple application which will let you do some basic settings on the first startup of KDE3.

The most useful feature for me is to tune the desktop towards performance or more desktop effects. (i.e. the 3rd page of kpersonalizer)

Experienced KDE4 users might know how to configure KDE4 desktop for minimal CPU and memory consumption, but new users cannot, with kperonsalizer, everyone knows we can set-up a KDE 3.5 in a low-resource machine with it: just drag the the slider to the left.

Yes I know in KDE4 that we can use a simpler style than oxygen, we can remove some modules in krunner, we can disable kwin composite, we can disable panel background and wallpaper or blah blah, kpersonalizer gives new user a much straight forward way to config all these.

Is that possible for KDE4?

I think someone is working on some kind of "Welcome" widget. Not sure though if it will contain options for configuring certain aspects.

Cheers,
_

I found that the other day. It is apparently a screencast of the welcome plasmoid, currently in playground.

http://www.youtube.com/watch?v=Uz8-nmcWb-c

I am not sure that it exactely matches your needs but developpers are probably opened for suggestions to improve it.