It's worth pointing out that applescript has no hooks to read the gang or level settings in the default settings
You are going to have to manually copy the information from the settings window and enter the information manually either into lists in a script or into individual OSC cues.
If you have limited scripting ability then the OSC method will probably be far clearer. Basically put a fire all group on a hotkey and put however many OSC cues you need to set the crosspoint levels and gang names for your set up. With cut and paste this shouldn't take more than 10 minutes. If you want to clear a gang use /cue/*/gang/0/3 ""or similar to set a crosspoint off use -120 (or a figure lower than your minimum volume limit.. I've used -70)
Here's a screenshot which should show you exactly what you need to do, you will just need more OSC cues. Then select ALL cues and hit the hotkey. It will ignore any cues that aren't relevant.

So basically if you had a 16 output device and were using audio files with up to 4 channels you would be looking at 128 OSC cues within the fire all group to set the level and gang of every crosspoint. You can put in a few OSC cues at a time to check they have the desired effect. As long as you don't edit the cue names of the OSC cues they will show what you have in the custom OSC message in settings so you can quickly check your settings from the cue list.
Mic