ChD, the C-17 is indeed a screwup conspiracy like Rosswell. There the conspiracy was also screwed up, as there was none
C-17 is a nice aircraft, well suited for the job (in contrast with the FLA, which still exists only on paper 20 years after the planning started...).
A clause saying the aircraft cannot fly at airshows is probably included to limit the number of hours on the airframes to the minimum operational requirements of the customer.
Last weekend at Leeuwarden, a B-2 and F-117 did not show, despite having been semi-comitted they had been withdrawn a week or so before the show (but after the programs had been printed of course).
There was US participation, but no flying display. Static included one (1) MH-60, one (1) C-21 and two (2) F-15Es. Boeing and Lockheed-Martin were both there with mockups for their JSF contenders, Boeing were even considerate enough to paint in in Dutch AF colours for the event.
The term "World's largest aircraft carrier" for Brittain came into being in WW2 with the stationing of the 8th AF for the bombing campaign against Germany.