Satoshi had extensive knowledge and well developed skills in cryptography. He obviously had a long-standing interest in it, and by extension in enablers of secrecy and anonymity. So it's not surprising that among the repertoire of skills be brought with him was a pre-developed capability to cover his tracks and behave in such a way as to avoid dropping any real clues to his identity.
Like others I doubt Satoshi is more than one person:
1. Multiple people increases the risk of someone slipping up and leaving clues to at least their own identity.
2. Multiple people would be more likely to reveal conflicting goals, motives, internal dissension and so forth in "Satoshi" posting, for which I see no evidence.
3. Increased odds that one of the Satoshi team would have broken ranks at some point and spoken up.
4. I believe the whole working concept of bitcoin had to be contained within one mind to thoroughly understand and initially conceptualize it and make sure there were no fatal errors in it. I tend to believe an effort to create something new on the scope of bitcoin would have gotten "hung up in committee" if multiple people had tried to work on different aspects of it. The end product would have been slow in coming, and would not have worked cleanly until after a lot of bug fixes, emergency changes and optimization. Not that bitcoin was perfect out of the gate, but on the whole there was a cohesiveness and refinement to it that makes me suspect a single diligent mind put a lot of mental effort into it, anticipating and resolving problems with it before they became a reality.
All of those are excellent points. Obviously Satoshi is brilliant, knows what he's doing, and had the foresight to know that his creation -- in spite of all of the good it can do -- had the potential to ruffle some very powerful feathers who may not like the idea of decentralized currency.
I suppose one could have approached this from a project management perspective and planned backwards from the main milestone. Some of the dependencies in the plan of reaching the main milestone would have been "how to remain anonymous."
