No, I didn't use an agent. As far as I remember, after I submitted my application it asked me to open up an immiaccount for the sponsor quoting my application number. It then asks the sponsor the same questions they requested from me in the application form (but from their perspective). This is the same as Form 80 - if you have filled it in and scanned into your application then you should be fine, however I remember some people here complained they had done this and were then asked in RFI to open up the sponsor's immiaccount to fill in this information nevertheless! Perhaps check with your agent?
On the application status, this is what Home Affairs website says:
Check your application status
If you applied online you can check your visa application status in ImmiAccount.
We assign a status to your application to show progress.
The status shows next to your application in 'My applications summary'.
Incomplete means you have started but not completed an application.
Ready to submit means you have completed an application and can submit.
Submitted means you have submitted an application.
Received means we have received an application from you and can assess it within the current processing times.
Initial assessment means we are assessing your application.
Further assessment means we are assessing the information we requested from you.
Finalised means we have made a decision. We will notify you by email or post.
Note: The application status for My Health Declarations and Partner sponsorship forms will always display a status of submitted and will not change to a status of received.