On the flip side the extra cost added to a licence would disadvantage , say a family with one car, with two parents with licences and say three teenagers with a licence, (intotal 5 licences one car)
Or people and pensioners etc with a licence and no car (ie the cook)
that would like to keep their licence if the need arises to use it ,or for proof of identity etc,
or so they can sell their demirt points to family members 
I think disadvantage is the wrong word. The quote from the MCC of NSW was about addressing inequities in what is supposedly a 'user pays system' ... so my points still stand.
A user-pays-system where only one-in-five users pays (as in your first example) is grossly inequitable to others within that system. If that system also allows for rorting (as in your second example) the injustice is further perpetuated.
Short term or casual users should pay a slight premium just like every other 'system' ... but that should also provide them with some flexibility. ID may be a convenience but is also an irrelevance to the discussion (I know people that have never held a licence yet can still identify themselves).
Of course the MCC of NSW is looking at improving things for a select group (mostly Harley owners ... but also including, say, modern big-Ducati owners) ... and it appears we all have our own 'angles' - but in this case I am the only one making any sense
Whilst I admitted that the class of vehicle may determine the extent of damage done (I addressed this earlier) ... it is the licence-holder that determines whether any damage is done at all - so that should be the basis of the 'payment'. If licence-holders were all capable of rational thought, it may actually make the roads a safer place to be.
