Can I apply for a retirement visa in Thailand using Australian bank funds and extend it from within Thailand?

A question for those more knowledgeable than myself.

I will be applying for a retirement visa from the Thai Embassy in Australa (Australian passport and citizen)

I will be using banked funds in an Australian bank equivalent to 800000baht. Which I believe from reading their website is acceptable. I am retired and my pension is paid directly to the account I will be using as proof.

Can this visa be extended from within Thailand after the first 12 months?

Can I use a combination of banked funds and pension income for the extension from within Thailand?

Pension income is 36000 baht per month.

How many extensions can be obtained for original visa?

Will I have to transfer original funds and pension income into s Thai bank account.

TIA