i did removed kde files from my install, for the latest update from kde 4.6.5 to kde 4.8.3
i ended with only console tools but os kept functional, i could run synaptic and install the new kde in console
you would have to install e17 first, then remove kde core and other important kde files while running e17, it will pull alot of files with it, if it pulls e17 too, then don't remove certain files, it will say what it wants to remove with it
if you are ready to break it if the procedure doesn't work, i would do it but since it is easier to have both e17 and kde without any problem, i wouldn't remove kde, just leave it unused, just as i did in the pat with gnome2, i had it as a backup desktop but in 2 years never used it so removed it