The "xfce4-settings dumping a core" problem, has been there for a while. When I run xfce4 by having "/usr/pkg/bin/startxfce4" in a user's ~/.xinitrc file and starting the xserver by manually invoking "startx" in the console login shell (not running xdm or similar) it puts the xfce4-settings-h.core file in the user's home directory, if that helps you to further debug...