Hi @KyoDude , I have lived in Sydney since 2012 and based on my experience (to answer your questions):
1) Most Filos live in Blacktown and suburbs around it (Western Sydney suburbs)
2) A lot of Filipino groceries in Blacktown (and restaurants too), I've always bought my stash of Filo groceries in West Ryde - Manila Mart (just across the station) or in Chatswood - Manila Sari Sari Store, when I'm in the area. The latter 2 are the most accessible if you live in the inner Sydney suburbs
3) Most families would ask their family friends to babysit their children. Incidentally, a lot of Aussie families would take their children to daycare centers.
4) Reasonable rent depends on the area you will be settling down in. CBD apartments/houses can cost you from AUD 1,000 rent per week minimum, almost the same price with inner suburbs. However, farther areas can set you about AUD500 for a 3-bedroom apartment, bear in mind that transportation can take an hour of your time to the CBD.
5) My brother and I try to stretch our AUD50 budget for 1 and a half weeks, we buy after hours (most supermarkets slash down prices for meat and other things like bread during late hours), it helps that I'm a chef as well so I get my meals from the restaurant, less household expenses for us.
Cost of living is not as bad as most people think, salaries are top notch even for someone with a career like mine, I can live comfortably and still afford at least 2 overseas vacations a year. In the end of it though, it's still up to you with how you manage your budget.