• Innate fears - Explained here why I'm not too afraid about AI risks.

You read fiction, some of it is made to play on fears, i.e. to create more fearsome scenarios. The ratio between fearsome, and nice scenarios, is set by market.

• Political orientation - Used to be libertarian, now not very political. Don't see how either would bias me on AI risks.

You assume zero bias? See, the issue is that I don't think you have a whole lot of signal getting through the graph of unknown blocks. Consequently, any residual biases could win the battle.

• Religion - Never had one since my parents are atheists.

Maybe a small bias considering that the society is full of religious people.

• Xenophobia - I don't detect much xenophobia in myself when I think about AIs. (Is there a better test for this?)

I didn't notice your 'we' including the AI in the origin of that thread, so there is at least a little of this bias.

• Wishful thinking - This would only bias me against thinking AI risks are high, no?

Yes. I am not listing only the biases that are for the AI risk. Fiction for instance can bias both pro and against, depending to choice of fiction.

• Sunk cost fallacy - I guess I have some sunken costs here (time spent thinking about Singularity strategies) but it seems minimal and only happened after I already started worrying about UFAI.'

But how small it is compared to the signal?

It is not about absolute values of the biases, it is about relative values of the biases against the reasonable signal you could get here.