Who binds the public key to the real-world identity and the identifier used for transactions?
Right now, nobody. However, anybody can see the NFTs at your wallet address, which is tied to each of your transactions. Prism is being developed to create unique and verified NFTs that contain identity information in their metadata. Thus, you will be able to identify the person to whom a wallet belongs should that wallet contain an NFT with identity.
Where is confidential data held and how is access to it controlled?
It depends on the context, but if you include metadata in a transaction, those metadata will be publicly available. However, you can always encrypt your metadata. When you encrypt metadata and attach it to a UTXO, whoever else has the secret key to decrypt those metadata will be able to read decipher it, but nobody else will be able to.
What tools do individuals have to ensure they avoid disastrous errors?
We recommend that you keep your mnemonics, spending passwords, and keys private and in secure locations. You might etch your mnemonics into aluminum so that even if your house burns down you will be able to recover your wallet. Otherwise, keep yourself educated, and do not fall for scams!!
How is access to on-chain metadata controlled to prevent re-identification? Blockchain ‘anonymity’ didn’t help Ross Ulbricht.
Everything on the blockchain is publicly viewable. Everyone downloads a copy to run a full node. Cardano is a way to validate and secure transactions. If privacy is your goal, we do not have very many tools set up for that yet. Feel free to develop some =^). You could even submit a Catalyst proposal.
When 51% or more of consensus participants validate any transaction for recording on-chain, against what evidence are they validating?
Each transaction is broadcast, and the slot leader creates a block from all of the transactions in a given slot. That block is then broadcast to the rest of the network. The network relays the blocks until everyone has a copy, and each time a block is relayed, information about the sender is verified. See Ouroboros Praos for the set of properties tested when receiving a transaction.
I hope that was helpful =^)
