can I ask why? What can you use the pink ID card for at immi that the passport can't? Nothing I presume - except you don't have to bring your passport and the pink ID card is obviously always on you.
A lot of people say that but that is not true - whether you have to go in person or not the 1st time depends on your immi! I did my 1st online and that was accepted! I tried because someone in this group said his 1st application was approved and he did it online. I would say try online first - it might save you a trip and the worst that can happen is that it's rejected and you have to go.
actually you are on your 3rd extension of your permission to stay. The visa was an entry permission and was replaced when shown to immi in the airport with a permission to stay - the length of that permission depending on visa. Very important : remember the TM8 (re-entry permission) before you leave - otherwise you'll have to start all over!
you don't renew your retirement visa - you renew your permission to stay. That's why it is called extension of stay. Always ask your local immi for their folder where they describe the requirements since they can differ (slightly) from immi to immi.