My guess is that David Kleiman was the greater half. Wright seems a meglomaniac. Pretty terrible as this has lead Core to revoke Gavin's commit access. IMO bitcoin's future looks bleak, and Ethereum will surpass Bitcoin as the preferred public blockchain.
No doubt. I expect the marketcaps to flip within a couple of years, if not sooner. I do think that Metcalf's Law plays into the value of BTC and ETH, and as it stands, bitcoin is at full capacity and will remain so for an in-determinant amount of time. Ethereum, on the other hand is growing quickly.
Yes there is. According to Andresen, he signed a message of Gavin's choosing on block #1. He was very close to Satoshi, and IMO he is half Satoshi, but that Kleiman was the greater half. It looks like Wright is limited in his ability to demonstrate irrefutable proof.