The Comet 4 was indeed used worldwide across the BOAC network, Transatlantic, to Australia, etc. Notably it could get into the old Melbourne airport at Essendon which the 707 could not, giving something of an advantage (I believe something to do with runway strength as much as length) until Comets came off the run, when it was unserved until the current Melbourne airport was opened. By the end in 1966 Comets had come down to medium-haul trips to Africa. They were effectively replaced by the standard VC10s, which got into the performance-limited airfields of Africa which the BOAC 707s could not.
Regarding cabin crew, a TV programme a while ago (maybe the Heathrow 50th anniversary in 1996) had a former C4 cew member saying that the Comet in the rear galley (remember how close the exhausts were to the fuselage) was the noisiest aircraft ever, and they had to resort to standardised handsignals among themselves.
Although they were all withdrawn by 1966 one was kept for a few years as an engineering trainer at Heathrow, in BOAC livery, and appears with a 747 on the cover of a book about BOAC (not advertising the book just showing the historic photo)
BOAC: A History (Revealing History)
Nowadays you would say this was Photoshopped as the early BOAC 747 in the foreground did not overlap with the Comet in the right background by several years, but it was quite possible.