At http://enlightenment.org which is Enlightenment's homepage, you can get a Slackware package for e16, but not e17. You'd have to compile it from source to get a copy of e17.
Don't use Enlightenment. It is based directly off of FVWM. It is a resource hog and KDE is just flexible enough. I had problems with KXDocker too like that, but I got my icons to stay on there by typing in something for every entry possible in the configurator.