I read the AUS/NZ permanent residence is infinite. Other countries require perm to be renewed after 5 years or so.
1) Is it same for AUS/NZ?
2) Is it same for minors too ?
Australian permanent visas do not need to be renewed, as long as you remain in Australia and do not travel overseas.
However, if you do travel overseas, there is a limit in terms of a "travel facility". From the Department's web site:
When you are granted a permanent visa, you are usually permitted a 5-year travel facility. This means you can leave and re-enter Australia as many times as you like in the 5 years from the date your permanent visa was granted, as long as your visa remains valid.
After 5 years, your travel facility expires and you will need to apply for, and be granted:
- a Resident Return visa - if you wish to re-enter Australia as a permanent resident or
- Australian citizenship - if you wish to travel as an Australian citizen.