Not ALL or ANY of the following conditions. So it's unclear, at least to me, whether satisfying any of the conditions would make us affected.

For example, it says "For the purposes of this Act, 'age-restricted social media platform' means (a) an electronic service that satisfies the following conditions"

They apply similar definitions as the EU in their DSA. Although Australia's are a bit more blurry.

A cursory read of Section 63C of the Social Media Minimum Age bill leads me to the conclusion we're not affected by it.

What are the criteria for social media according to Australian law?

That we can't

How a site would 'ensure' anyone under 16 doesn't access it