Definitely no requirement to readback two behinds as per ATC, Trojan is correct, don't have a link but its in the AIP's, just checked it a few weeks ago.
As for localiser frequency I have been prompted a few times for not reading it back in Sydney. I see what you mean about it as a check but at the end of the day they are instructing you to use that runway are they not? As in they are checking that your ATC instruction for the appropriate runway has been correctly interpreted by you?
Don't get me wrong I don't want to read it back, its a pain in the you know what!