Stating that you are established on the localizer is NOT a readback, therefore it is acceptable.
Reading back an 'on ground' airways clearance starting with your callsign, might not technically be correct but isn't it reasonable to start off with ''Etihad 141 is cleared to Mumbia via...''.
As far as Fife and Niner are concerned, they are remnants from past generations when VHF was not so good and HF was more prevalent. The relevant documents should be changed to reflect current radio capabilities.
Cleared ''Descend to'' is not a wrong ATC call because pilots and ATC are supposed to say either, FEET or FLIGHT LEVEL. Since flight levels always have their base below 20,000 feet, then a ''cleared climb to'' or a ''cleared descend to''.....should not be a problem if everyone always included.... Flight Level or Altitude (feet is the other option below transition altitude)
The OMA clearly states that either Feet or FL is to be included in all altitude readbacks.
I know that some pilots will think this whole discussion about proper RT is a bit pedantic but it is not. From my experiences, pilots who don't follow proper RT are also more inclined to not follow SOP's are also usually the least competent, just my opinion though.
Non-standard RT was the biggest reason that so many American pilots were unfairly lumped into a bad category. Agreeably, many US pilots were ****e on the radio, but fly with an American who does not take offence when this deficiency is pointed out and I guarantee they will be one of the best colleagues you could have on the flight deck.
Communication is one of the most important aspects of our job and since we don't 'see' ATC, we lose up to 50% of the clues and signals necessary to properly determine what is being said. That is why STANDARD RT is so important.
India is the best example (followed by Africa), which clearly demonstrates that when improper RT procedures are common, safety is reduced.