I'm not in a position to argue as you obviously know more about the VC10 than me. Give me a quote from a reliable source & I will believe you. I have no idea what a Utility certification means in this sense but this doesn't sound like ARB (Air Registration Board) terminology to me. The CAA was not formed until 1972.
I have no doubt that modern arliners are tested just as stringently if not more so before being certified to carry passengers.
Modern a/c are tested of course!! In order to define their flight envelope. In the case of the VC10 it was specifically designed as a high performance a/c and thus it's flight envelope is considerable compared to ordinary jets!!
If my memory serves The actual certification was "unrestricted" which equates to "utility". The certification nowadays is "normal" "utility" and "special" "Special" is full aerobatic capability. In otherwords one can chuck it about the sky and nothing will happen to the airframe.
"Normal" is granted to a/c that can safely recover from +3.5 g and -1.5g manoeuvres. (all modern jet transports) "Utility" falls between the two. I stand corrected but I believe the Vc10 is rated as +5g and -3.5g.