Well, i recognize this wont answer your interesting questions, but as a mere example i've seen along all these years a quite handful of A300's and 767's taking off in Flapless config..
(regarding trailing and not leading/slats)
Photos: Airbus A300B4-622R Aircraft Pictures | Airliners.net
Photos: Boeing 767-201/ER Aircraft Pictures | Airliners.net (interesting comment)
Almost Flapless in this one:
Photos: Boeing 757-2G5 Aircraft Pictures | Airliners.net