Could Satoshi Nakamoto be the CIA/NSA?
Yes, (s)he could be. Would it matter? NO, NOT AT ALL. Nobody cares if he was just a lone genius, or CIA or NSA or Spetsnaz or North Korea's Great Supreme Leader Kim Jung Un himself.
What if bitcoin miners are being used to generate rainbow tables for cracking password hashes.
Since Bitcoin is open source, we all
know what is being hashed. And thus, with absolute positive 100% certainty, we know it's
not password hashes.
What miners are calculating is hashes of hashes of merkle roots (=pseudorandom hashes on data that is influenced by everybody, and nobody has control over) plus an increasing random number (nonce) that is controlled by individual miners. So this has exactly
nothing to do with password hashes.