and you have no other indication that you are not cleared to land
Sorry CloudCutter. The fact you have no indication that you are cleared to land is more to the point. Not only is it a breach of the CARs and SOPs to land without a clearance, more importantly, you don't know if someone's cleared to cross, cleared for an intersection departure and so on.
If it's OK to breach these rules - where do you draw the line?
There in NOTHING unsafe about a missed approach - I used to do up to 10 a day when teaching circuits - I wasn't flying!! - and I would say a major airline the size of QF would probably average one every few days (as a rough guess). It's a routine procedure.