Children on permanent care orders rarely if ever see their parents. Part of the reason they are on that order is because either the parent has serious issues that they have failed to address over a long period, or they have voluntarily signed over their rights.

You may have issues getting a small baby, as part of DHS's goal is family reunification, and always try to give the parent the oportunity to redeem themselves. By the time it has got to the point of a permanent care order, the child is usually a toddler or older, but I have known of a couple of babies on PC orders so it is possible.

It has been a few years since I worked in vic in child protection but from memory I think at most they are only allowed 2 visits a year, as it is seen as unsettling for the child.
Not necessarily at all. Even parents with big issues usually have 4 visits a year, and this can be more often. It depends on the desires of the birth family, and what it is considered in the best interests of the child.

Keeping contact with birth families is important and is encouraged as long as this can be done without harming the child.

As lil chookie said there is quite a bit of variation in visitation.

In Vic, permanent care parents can be called Mum and Dad. Again, It would depend on the circumstances- how old the child is coming to your care, what relationship they have with their birth parents, and previous carers.