I have not seen widespread data on symptomatic vs unsymptomatic cases however during the most recent NSW surge around 5-7% of new infections ended up presenting

I have not seen widespread data on symptomatic vs unsymptomatic cases however during the most recent NSW surge around 5-7% of new infections ended up presenting to hospital at some stage. Testing was widespread and likely highly compliant - daily testing stats were available, NSW at one point was having 180k tests per day (PCR). People were notified of sites of exposure (or via checkin apps) and asked to test. Given it was PCR, false positives were as you would expect quite low but there were at least 2-3 false positives I recall being discussed in the media. In answer to your final question - no - they were PCR confirmed cases. There was also a high degree of sequencing occurring to enable clarity on lineage transmission