You make everything so complex, something is bound to fail. Multiple connectors, switches, plugs (another connector), etc. I'd take a hard boat with a comfy seat any day...
Run the live off your trolling motor battery, or are you 24V? You may experience interference, you may not, in my experience. The odds of interference is less since it's not on the motor.
Not sure about Humminbird, but Garmin says not to zip-tie the transducer wire to the motor or pole, use electrical tape. Perhaps Humminbird protocol is different.
I don't have ladder stands. I do hunt from some boxes on green fields. I also hunt in the timber. Georgie boy and I are still waiting on your trophy pics, doubt that's going to happen....
I doubt you know a trophy, seeing you don't know what a sanctuary is.
Carry on.....