1) Look into your /etc/X11/XFree86Conf(-4) and try to find "Virtual Resolution" line. COmment it out (by putting # at the beggining of the line) and start X again.
2) You specify the windows manager you'd like to use in .xinitrc file in your home directory. Create it in any editor and put inside
if you'd like to run KDE (stargnome for GNOME).
3) Before accesing CDROM/floppy you need to mount them. Floppy:
(or, if no success: mount -t vfat /dev/fd0 /mnt/floppy)
(or: mount -t iso9660 /dev/hdc /mnt/cdrom where you should replace /dev/hdc with teh right name, hdc means secondary master drive, hdb is primary slave and so on).