All good stuff - but who is to say what is correct?
The FAA say they will accept "Roger" in lieu of a readback of any (or all) item(s) in a full route clearance - they still say "ready for take-off" - they still say "cleared the runway" etc.
The Limeys are on edition 13 of their own R/T phraseology book - which no other country follows.
ICAO has said that Limey R/T manual version ONE is to be the (acceptably low?) standard of R/T for the industry.
All three of them see themselves as (sufficiently) correct.
I think it is a battle that will never be won - by anyone.