I hope that you have figured this out by yourself already. I have had the privilege of working with IVDs in the past few months and will try to answer your questions to the best of my knowledge
After our device is cleared by 510(k), it comes along with a CLIA waived letter. I have a few questions...
(1) what is the purpose of this letter?
The CLIA waiver letter indicates that your device is simple to use and the risk to harm due to erroneous results is considerably less. So for the diagnostic laboratories that wish to use your test devices at their facility, they will have to apply to CLIA for a certificate of waiver and can then proceed to use your devices.
(2) when will we need it? (when we are inspected?)
"CLIA requires all facilities that perform even one test, including waived tests, on “materials derived from the human body for the purpose of providing information for the diagnosis, prevention, or treatment of any disease or impairment of, or the assessment of the health of, human beings” to meet certain Federal requirements. If a facility performs tests for these purposes, it is considered a laboratory under CLIA and must apply and obtain a certificate from the CLIA program that corresponds to the complexity of tests performed."
Which would mean that laboratories need to register themselves before they carry out tests with your devices at their facility.
(3) it states that when device name is changed, revised labeling should be submitted to FDA. is that necessary...? (because when we change device name we will do the listing anyway)
Any changes in labeling must be submitted to the FDA in my opinion because the laboratories are relying on your labeling material in order to perform the test as directed and hence any changes to labeling would be deemed a significant change.
Hope I have shed some light on your questions. I am not able to post links but you can refer cms . gov and look out for "How to obtain a CLIA certificate". I've quoted some text from that document.
Cheers,
Aniket