Background, Oz rules: A clearance to conduct an approach is an approval to descend as required but not below LSALT/MSAs etc (unless a descent limitation has been imposed) & thereafter IAW the procedure. So...
After the 1st instruction:
1. No
2. Yes, if you don't clear lower in a timely manner
3. N/a
After the second instruction
1. Yes.
2. No
3. Whatever they decides is best for them on the day. You've just cleared the a/c to descend as required from 6000 to 3000 to get onto the approach (and below once established in some part of the procedure eg a sector entry, hold, interception etc ).
Me: ehh, pylot.