I think zealot is the correct word.
Breeze, I think Tao is best treated as an agnostic.
It's not so much that he's banging Dawkin's drum, as much as he sets a very high level to his own personal beliefs. I read more uncertainty than certainty in his posts.
However, I think Tao is unfairly seen as some form of Atheist's Bible Thumping Materialist - and becomes a target of general criticisms of atheism, materialism, and science, even though Tao holds personal views rather than a specific doctrine - which naturally irks him because it misrepresents him. That's my reading anyway.
Tao, could you also be careful about using personal attacks, please? I'd like to avoid any direct name-calling, please.