Exactly that.

Yes, fits right in!

Well the only evidence I have in favor this theory about high IQ is anthropics itself. And it should not be taken as very strong evidence. But perhaps I could make a bit stronger case, if we assume version of anthropics, where only thinking about anthropics counts as observer moments. Then one would have to have at least as high IQ as it is required to understand anthropics in order to think about them.

It indeed does apply to almost anything.

This is a great list, thanks!

Would it make sense to outlaw talking about doomsday argument?

And then I might respond by slicing into the definition of observer, creating "half-observers", and moving smoothly between observer and non-observer...

Do you have this written down somewhere in more detail? It seems that for this to work one needs to assume the gradual appearance of consciousness, something like rock<beetle<mouse<ape<human. Will this work if one assumes consciousness to be binary, that it either is or it isn't?

So what you are saying, is, before one knows his birth rank, one should assume infinite universe? This does actually corresponds to evidence about universe size, but not about human population size.

Lets say you do not know your birth rank at first. Then someone asks you to guess whether the universe is around 200 billion or some very large number. Without any additional data you should estimate 50% for either one. Then you get to know that your birth rank is around 100 billion. Do you not then update, that smaller universe have bigger than 50% chance estimated previously?