1. In short and simple - your IDP/licence is already gone.
It became automatically suspended when you blew that much in a roadside test.
You are already no longer able to lawfully drive in Australia.
And no, there is no stay/ grace period etc between now and court.
You're done driving.
2. What you get depends on your previous criminal history,
and on the surrounding facts and circumstances of your offence.
Have a read of
this (note: this is not my firm).
3. The Local Court can't order you to be deported as such.
But, it can convict you of an offence which could in turn
lead to your visa being cancelled on character grounds.
As a cleanskin, who didn't kill anybody in an accident etc,
and shows suitable remorse (as distinct from mere regret at getting caught)
you're less likely to be going to gaol.
4. There's no need to tell you that you do actually have to turn up to court, surely?