warrenty issue

I have my Z30 in forwarrenty for, what appears to be, an Iris not funtioning. I got the call that it was ready for pick-up. When I got there I found out that all they did was update the firmware. I was not impressed by the service center. I think the technichian just serviced a toaster before looking at my camera. I'm sure they are good at toasters but this is a camera. I showed them the evidence that the iris problem was still happening so now they are going to replace the lens. I hope they clean off the crums befor they start. My question is when I get my camera back what can I do to be sure that any alighnment is correct, or any dust (crums) might be on the sensor, or anything else I should be concerned about. Thanks in advance

Steve