Hi there
.... 1 Does one need a permit/permission to fly from Perth-Sydney?
2. Is Qantas offering any food on the above domestic flight? ....
There is currently a ban on all overseas travel from Australia, with few exceptions.
No meals (or inflight entertainment) are being provided (just water) on Australian domestic flights at this time. It’s BYO food, currently.
It may be an idea to check current information on international travel via this link:
https://www.health.gov.au/news/healt...for-travellers