Hey Shealan19.

Erm, im confused with what you mean.
If you get registered under 'limited registration in the public interest', then YES, you will be allowed to work in Sydney. And YES, Sydney is in New South Wales. If you get registered, you can work where you want.

With re. to NZ.
It'l take about 4-5 months to go through if you do it correct.
You need to have worked for at least 12 months where you qualified prior to applying.
Registration is not guaranteed, so if you dont satisfy the NZ board, they wont register you.
You DO NOT have to work in NZ if you get NZ registration.
You get NZ registration. Then if successful, you are eligible to apply for 'General Registration' with the physio board of Australia.

Finally.
I an on Limited registration. and iv had it renewed for another year in line with renewing my Working holiday visa. Yes, I am in a hospital, in the city. And yes, there is much support. I work with around 20 other physios. Work on my own, but there is so much support that you never feel isolated.
If you look around, you can find good work.

Hope that helps.

Liam.