Xconfigurator is typically located in /usr/X11R6/bin/ so you might want to cd to that directory and type "./Xconfigurator" making sure you capitalize the X (obviously type it without the quotes). =) Also, as for your mouse situation, do you have a serial mouse or a PS/2 mouse? You may want to make sure that the file /dev/mouse exists and is pointing to either:
a) /dev/psaux <-- if you have a PS/2 mouse
b) /dev/ttyS# <-- if you have a serial mouse where the # is either 0,1,2,3 depending on which com port your mouse is on.
(0 is com1, 1 is com2, etc..)
To make /dev/mouse point to either of the above use the command "ln -s /dev/??? /dev/mouse" where the ??? is either a) or b) above.