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.
always ask your local immi for the folder they have for their requirements because they are not all the same from immi to immi. And your non-o was an entry permission and was basically used when you entered and replaced with a permission to stay - the length of which is based on the visa type.