I never fill out the card given out on the aircraft (or that is available in the arrivals hall). The questions ask by the GE Kiosk are similar and the card that is printed out is what you are supposed to give the customs ( CBP ) agent as you leave. The whole purpose of GE is not to have to do any of that.
DEN
This is wrong. The kiosk asks "have you answered "YES" to questions x trough y on the form". This presupposes you have filled the form beforehand. At every US entry port I've been, I've been asked for the card, together with the kiosk receipt. And you definitely need to have filled out the Canadian declaration card when entering Canada.