whats wrong with using the unsupported web based exec.php function at
http://<m0n0wall>/exec.php ?
It allows the execution of shell commands as well as file up/download (though not permanent of course). It clearly helped me tremendiously while testing out new functionalities.
What i have been using ssh for is to tunnel through one m0n0wall device to access another. In our environment we have some very strict rules. and this is an essential hack for us. Its a large investment firm and we are using this internally for ipsec connections across the world. Ssh is needed in case the link goes down.