CIO takes an enormous time now-a-days to send our file to the local visa office. That's the reason the CIC guide says to deposit a copy of our original apps to the the Visa Office alongwith all supporting docs, after we get the 120 days letter.
For the change of address, I guess u can't do much now unless u send the 2nd stage docs to the local CHC. There, with the cover letter [as well as on the apps] write the new address. Meanwhile fax a letter to the Central Processing Unit, Sydney-NS, as well.
Most probably now that your 120 days have elapsed, u r not likely to be anymore accepted b the CHC. They r getting strict about it day by day. But, u can always try with a suave cover letter explaining your factual position. But, I'm afraid if they yet do not accept your 2nd stage docs, u might loose your apps fees.