Once the programs are removed and you just have the directory for them left just open a console and rm -f /Path_to_directory__for_removal you may have to use -rf if there are sub-directories.

The KDE programs are the ones that do not depend on the kdelib4 so they would not have been removed anyway so you have no choice but to remove them by hand as for the knoppix leftovers that depend on the sysvinit your best off leaving them alone it may not be the best solution but unless you want to try a fresh install of some other flavour of Debian then you will never end up with just the packages you want on the machine.