You must have choose not to start kdm during the install try kdm instead of startx to start the k display manager. If kdm is not installed then apt-get install kdm after it install on each re-boot it will start and give you a graphic login. To automatically start kde as your user (ie. no login just straight to KDE) go to the KDE Control Center -> System Administration -> Login Manager -> Convience and choose the options there.

For the mouse you should be using the IMPS/2 protocol in the /etc/X11/XF86Config-4 file for the mouse. The relevant section for a ps2 mouse:
Code:
Section "InputDevice"
        Identifier  "PS/2 Mouse"
        Driver      "mouse"
        Option      "Protocol" "IMPS/2"
Option          "ZAxisMapping"          "4 5"
        Option      "Device" "/dev/psaux"
        Option      "Emulate3Buttons" "true"
        Option      "Emulate3Timeout" "70"
        Option      "SendCoreEvents"  "true"
EndSection
You will have to logout and choose restart X server to have the changes take effect.