I think for the most part you will have to end up braking eventually when shifting to N (like coasting up to a stoplight or stop sign) but that still would use less gas than leaving it in gear and using gas up until you have to DFCO.
Yeah, hooking up an LED to go off when Eco cam is on is great. I don't like how in most other Honda vehicles there is a little ECO button that lights up when driving sanely (Honda Odyssey used this in 2006, I believe the Accord has been doing this since 2002) but they never put one in the Civic. Putting the LED in the dash is what I would do, that would make it more fun to drive IMHO, since I will be trying to keep the light on.
__________________
|