Yeah, that is interesting. My guess would be that he's saying a single node could operate at that scale for less than the total operations of Visa. That could be true.

As for the "scale ceiling", I think he's arguing that there isn't a quadratic (or higher) growth in cost. Which I think is also probably true in general. I haven't seen a convincing argument against it at least. I'm aware of the quadratic cost in signatures, but that's as the size of a transaction grows rather than as the number of transactions go.

Really a very different perspective than certain key developers today who emphatically claim that 8MB is scary and dangerous.

Parts of these emails are indeed not legit, but what you go on to say might well be worthy of further investigation. Thank you.

If these are legit, it would be a confirmation that Satoshi mined the block #5326, as block reward from that block is sent by Satoshi to Mike Hearn.

Mike: I sent you 32.51 coins, my bitcoin address is 1JuEjh9znXwqsy5RrnKqgzqY4Ldg7rnj5n

Satoshi: I sent back 32.51 and 50.00. (https://blockchain.info/address/1JuEjh9znXwqsy5RrnKqgzqY4Ldg7rnj5n)

This is interesting, because if you go back to the old ExtraNonce analysis by Sergio (https://bitslog.wordpress.com/2013/04/17/the-well-deserved-fortune-of-satoshi-nakamoto/), block #5326 fits the pattern of this early miner with a distinct ExtraNonce pattern, and would be the first (?) direct evidence, that this miner was in fact Satoshi.

"I will no longer be taking part in Bitcoin development and have sold all my coins." from https://blog.plan99.net/the-resolution-of-the-bitcoin-experiment-dabb30201f7

Im skeptical, but they probably are real. I wish hearn had published them prior to his exit from bitcoin and the development team as a whole.