As far as CASA exemption are concerned they are quite specific. The exemptions for RA-Aus cover the AIRCRAFT until CASR103 and CASR149 become law. Part 61 covers licences, which the recreational aviation certificate is not. For each SASAO such as RA-Aus, for issues such as medical fitness and recency the relevant operations manual is the official guide. All pilots still need to reference the AIP (all of it) so we are all "flying right" and doing things like giving way to balloons and landing aircraft.
What this also means is that CASA can't relieve an RA-Aus certificate holder of their flying privileges. CASA can initiate actions against certificate holders for Darwinian stupidity like flying drunk, flying too low over a festival, maintenance fraud and hurling abuse over the radio.
Does CAR166 apply to 10- and 19- registered aircraft and their pilots? Not all of it, because this regulation covers use of radios and other procedures at certified non-towered aerodromes which home built, experimental and low performance aircraft are not expected to use at the same time as RPT aircraft. Should you use a radio elsewhere if you have one? Up to you but read the regulations.
RA-Aus syllabus teaches the same circuit join procedures as appears in CAR166. This is not a co-incidence. In this way certificate holders shall meet the regulation requirement.
CASA tend not to prosecute SASAO certificate holders because when they violate the regulations, death often gets in first.