LEM
Your concerns on this issue were raised at the time Honeywell was selected as the vendor with this design.
The answers to your worries are apparent if you look closely at the operation of the panel switches.
When a mode engages the LED's in the switch illuminate. That is not something you can prevent. It doesn't matter if you touch the switch or not. It's software/hardware controlled from the DFGC and not a part of the switch function.
When you press your column disengage switch power is interrupted to the interlock system and when the mode disengages the final indication to you, the pilot, is the LED extinguishing (plus, of course the horn). The LED's are their own system unto themselves and are in fact independant of the switches.
The disengage bar is a "positive disengagement" mechanism that physically removes power from all of the DFCS flight control commanding subsystems. It's there in the unlikely event that your column switch fails in the "continuous contact" mode.
You'll notice that it takes at least twice the force to raise the bar as to depress it. That's to ensure that you don't accidentally raise it once you've used it in a problem situation.
The bar is not considered a normal means of disengagement of the DFCS and was designed to be left in the raised position.
One other little bit of trivia you may or may not be aware of; the two yellow panels behind the bar are illuminated. Not brightly enough to be seen in normal light but if you have a dark cockpit have a look and you'll see the light...:-)
Blue above the rest below