1.) In /etc/X11/xorg.conf under Section "Input Device"
did you set the protocol to be IMPS/2? THat should fix it IIRC.
2.) Edit /etc/X11/xorg.conf to fix the resolutions to be what you want, I run the following in 24 bit mode (edit the depth mode you use or all of them):
Modes "1280x1024" "1024x768" "800x600" "640x480"
ViewPort 0 0
3.) Did you run alsaconf to configure your sound card? Slackware should already support most sound cards from a full install.
4.) Sorry don't use KDE all that much so can't tell you.
5.) The last 2 cd's contain all the source codes for the packages on discs 1 and 2.
6.) Yes, I don't remeber exactly but if you google lilo and background you should get some info on it. Maybe someone else can post the instructions to edit /etc/lilo.conf to do this.