You audit the exact same way a Bitcoiner audits Bitcoin. You run a node. No substantive difference. No Bitcoiner is taking advantage of Bitcoin's transparency to verify the hundreds of millions of transactions inside 800,000+ blocks themselves. They're just relying on their node to do that for them.

No clue what point you're trying to make with that second paragraph. Makes no sense. Bitcoin is also open source and forkable.

Just because Monero uses more complex cryptography and math to verify (pederesen commitments and range proofs) doesn't mean you can arbitrarily and trivially trick anyone with a malicious copy. Any fake amounts would be invalidated.

I'm not attacking you either I'm just trying to understand what you mean by these things. I agree, everything has flaws.