What to ask a tradie
A good first conversation is specific. You are trying to learn who does the work, what is included, and what happens if the house is not as expected once the lining comes off.
You do not need to sound like a builder. You need the answers written into the quote.
The person in front of you
Ask who employs the people on site, who holds the licence, and whether subcontractors are part of this price. Ask for the licence number and look it up yourself while you are still deciding.
The work
Ask what is excluded. Ask what they need from you before they start, such as a clear room, a decision on tiles, or access to a switchboard. Ask how long the affected room is out of use.
Ask what they will do if they find rot, asbestos, or a live cable where the drawing assumed a clear wall. The useful answer is that they stop and price it before continuing.
Money and afterwards
Ask when you pay, what a variation looks like, and who warranties the workmanship after the manufacturer's warranty on a product. Ask for the invoice entity name so you can match it to the ABN or NZBN.
Then find a local business in the trade you actually need and have this conversation with them.
Common questions
Is it rude to ask for a licence number?
No. Licensed trades expect it. A public register exists so you can check.
What if they will only price it after they start?
A call-out to investigate is reasonable for a blocked drain or a roof leak. The investigation price and the repair price should still be separate, and the repair should wait for your approval.