Hi PMK,
The time frame will vary from person to person. It can take up to a month or more sometimes. Once you've passed the reference checks, you'll be advanced to the next stage which is medicals. The cost of medicals will come out of your own pocket and can take anywhere from a week to a month. Once you've passed all these requirements, your application will be forwarded to a panel for a final approval. At any point in the process they are able to deny your application if for whatever reason they find your application/references/medical unsatisfactory.
Flights & accommodation in Sydney are provided for the duration of EPs. I'm not sure whether you're given allowances during initials though.
Good luck and just be patient. No news is good news sometimes