If you still find some acpi features not working on asus and toshiba models, just edit the local rc file and add
modprobe toshiba_acpi or
then check the power settings in the KDE battery app.
you should now be able to control the brightness.
for fn function keys i used fnfx and fnfxd which can be googled.
acpitools which is command line and can activate asus leds or force fan to on if you laptop runs hot or back to auto, as well as suspend to ram and suspend to disk.