Hello John,
1 and 2)
In the DMX In action list there is a trigger called Receiving.
This generates a up and down flank when dmx is received or not received.
Using one of these flanks per action will allow you to enable or disable the action list GPI.
You may also have to stop all recordings activated by the GPI.
This is done by changing the playstate of a recording.
3)
You can limit the max output of a recording using the intensity.
There is no way of specifying a minimum value.
If you need live throughput from DMX in to DMX out.
There is a way to limit the maximum, however this is limited to 5 channels using the console and 4 recordings.
If you set the console / recording to output 200 on one channel and control the intensity using the DMX in.
Best regards,
Guido