Regarding total bandwidth, it wont be the case that every fiber connected house in Australia would start downloading at max 100 mbit at the same time. Just as it wont be the case that every 10 and 15 amp power point in every house in Australia will be run at full load, or every tap in every house turned on full, so it is just not necessary to have such massive bandwidth as that email implies.
This shows just how long we have needed the NBN for, this is dated 2003 and talks of Gigabit over fiber