- Are they entitled to free medical benefits across the board(including GP, medication, major illness, scans etc.) as elderly
No, not all free. They are entitled to the same things free as other Residents. (There has been talk by some politicians that the elderly should get free health care, but it hasn't happened so far - watch the news about the election for this.
http://www.nzherald.co.nz/nz/news/ar...ectid=11311349)
- Will they get superannuation benefits
I can't tell you this. It depends on a person's individual circumstances, including what country they came from and what pension they might be entitled to from that country, among many other factors. You and they would need to check it out with the superannuation people.