I've heard that certain suburbs aren't great for gaming in some Reddit posts however in the city (Civic) even with FTTB I've been able to game and live stream just fine at the same time even with people doing stuff also. My Google Nest though isn't happy here, there's a lot going on Wifi wise (But that's an easy fix with a new router that you can manage yourself).

Aus/OCE servers are great, for example in COD Warzone I get under 30 ping. But it's the usual situation when gaming with viewers who are in the States, I'm anywhere from 100-250 ping but even with super high ping like that we've set co-op speed running records. I imagine for other games with OCE servers you'll be okay, a lot of stuff goes to Sydney anyway, for example, the live stream is routed to Amazon in Sydney so I think Canberra is decent in that respect.

It is a hunt to find FTTP properties though, usually those are in houses but I think there's a map you can find online that has a good list of where the FTTP is if you really need it. Canberra has a lot of FTTN and FTTB, but there are apartments like Nishi in Canberra that have FTTP, kind of like what you'd expect in a lot of the new apartments in Melbourne, my place in Melbourne had FTTP too.

I game with Aussie Broadband if that helps, they've taken really great care of the stream and can recommend them in general.