Circuit joining "etiquette"
Within an ATZ I thought there were certain "rules" one was supposed to obey such as "conform to the pattern of traffic formed by other aircraft". If you are 100% sure there is no other traffic notwithstanding local noise and other procedures you don't need to conform therefore you may do a direct join. That said an Air/Ground facility is not entitled to provide an Air Traffic Service and there is always the possibility of a non radio which you may not be aware of.
Another rule is that all turns within the ATZ are to the left unless ground signals or the ground station indicates otherwise.
Depends a bit on the level of the local Air Traffic Service and the availability of radio. If in doubt, I ask what they would like me to do.
It is not within the remit of an A/G or AFISO to do this - all they are entitled to do is provide information and it is then entirely up the pilot as to what action to take. The only exception would be AFISO where they have jurisdiction over aircraft on the ground.
That said however you join keep a good lookout and listen out to build/maintain situational awareness.