Well, for me Kicker was always a lot more of a headache, but here's the simplest method to get the default Plasma settings back:
Yeah, you just pointed to the biggest problem for all using KDE4/Linux (Or is it Linux/KDE4).
It was a long road to become as good as free from command line which was, let's be honest, not a home user friendly environment. not after Win95 and the mouse etc. that openend up PC's to the masses.
We now enter with KDE4 a new era of "geek stuff" which the masses with reason will reject.
Saying that, thanks for this option, it will be of use in the near future while it indicates that a simple link "Reset Panel" can't be far out this way.
. Maybe even a overall user friendlier and more agile KDE4 will pop up at the end of the day.