... would Mmo (max. mach) and Vmo (max. velocity) be
rated higher than Vne?
One or the other. The basic rules for US certification for you to review are at
(a)
FAR 25.1505
(b)
FAR 23.1505
For lighties (or any aircraft for that matter) the basic certification data is in the Type Certificate Data Sheets (TCDS) which, for the US case, can be found at the
FAA's TCDS site.
... they were in airplanes that approached runways at twice Vne
I have no specific knowledge of the Katana .. but, I don't think so ...
... flew over landing strips at 220 knots and 1000 feet altitude
(Airbus 330 flying into Denver airport).
not the norm, I would suggest, but certainly not outside the routine capability of the typical airliner and crew ...