frontcheck
Whilst appreciating the tone of your mail, the irony of it is that the potential flaw in your para 1 is exactly what I am describing.
The check in agent is removing a layer of scrutiny, by using my name to check me in, not the PNR/locator.
As to para two, when I say e-ticket receipt, I mean the eticket receipt from the Amadeus or Sabre GDS, not some waffling 20 page print out from Expodobookers.
Sorry, from my perspective, it just looks someone working around the process.
At Paris, last year, the check in agent asked me whether I would like a window or aisle seat and I said I had 1F pre-reserved. "But that is in business class" she replied, looking rather surprised.
I refered her to the eticket receipt that she had not looked at, to confirm that it was a 'D' class ticket and then I got my seat - but it does make one wonder what reservation she was viewing.
Perhaps you are saying that you ask for the destination and then check the reference #, if so, that seems sensible.