Regarding anthropics, specifically this:

Is intelligence hard to evolve? Well, we're intelligent, so it must be easy... except that only an intelligent species would be able to ask that question, so we run straight into the problem of anthropics. Any being that asked that question would have to be intelligent, so this can't tell us anything about its difficulty

I think the line of reasoning is valid, it's just that there's a lot of confusion about probabilities and events to which the probabilities apply. Of course the probability of life arising - once in the whole universe - is high - very close to 1, given that we are very sure we in fact exist.

What we want to know is the distance to the nearest other-origin intelligent life, and that's where anthropics shouldn't be able to help us at all. Even if you subscribe to the notion that the probability of our existence is in some way proportional to the number of intelligent beings, that does not in any way whatsoever privilege a smaller universe with the same number of intelligent beings over a larger universe (with those beings spread further apart as measured in the sizes of the intelligent being).

It'd also seem that one could take a good look at the known laws of physics, think really hard thoughts that we can't think yet, and compute a good approximation to the density of intelligent beings in the universe. Which renders alternatives - same laws of physics, different density of beings - logically impossible.