Hi RyWolf,
in the remote on menu at the top of the control window you can set the broadcast subnet, so you could have each pair on different subnets.

As far as I'm aware the preset.txt file only contains preset info so providing you want the same presets on each machine then you can copy it from a master machine. You will have to close catalyst, copy the .txt file across and re-open catalyst.

I'm not sure what the command is. Is the control machine running catalyst? you can set up preset groups. In preferences set the remote preset ID for the remote machine and then in the cuelist of the control machine you can trigger a preset for a particular preset ID.

I know this doesn't totally answer your questions and you will need to do some testing, but I hope this helps

Paul