Hello! In recently installed Fedora 22 with KDE Plasma 5 the touchpad settings are not working properly. I don't know whether this is a problem with the touchpad or with kcm-touchpad module but it only allows you to enable/disable mouse click emulation. The options for one/two/three fingers are inactive, inactive are the options for the corners, inactive are some of the scrolling options, for the pointer motion and for sensitivity, or in other words, kcm-touchpad is almost unusable.
See also bug #1225579 As part of https://fedoraproject.org/wiki/Changes/LibinputForXorg libinput is used instead of (classic) synaptics driver, but it has less features, as you noted. To switch away from libinput, remove the package xorg-x11-drv-libinput and reboot. kcm-touchpad should then give more features (like edge scrolling customization) Unfortunately, for some, kcm-touchpad doesn't detect synaptics (after removing xorg-x11-drv-libinput). If that happens to you, see bug #1199825 tracking that issue. *** This bug has been marked as a duplicate of bug 1225579 ***