Yes, you can have all channels acssessible, but you can't mix them all on the same console, as you are limited to the 32 mix channels. In a pinch, you could allways submix some channels on the monitor console and make the submix available to the FOH console, if you add an iPad or a PC you could even do that submix remotely from FOH.
Should not be a problem to have all outputs accessible from FOH as long as they are routed. Remember, the typical setup would be to plug the S16 into the "A" on the monitormixer and go from "B" on the monitormixer to FOH, thus having to route everything at the monitormixer. You could also plug the S16 into the FOH, using two CAT5 to FOH, and you would then have the routing and the control of the S16 at FOH. Lots of options depending on what you want to achieve.
Haven't seen a single mention of being able to slave one console, but you could have preampcontrol via remote iPad/PC.
Maybe someone with the access to two desks could connect and route inputs from one to the other, and then see if the preamps respond to the controls of the remote desk? It should be quickly done.