Who is the intended audience for this document?

Every smart person who is fairly persuaded to care about AI risk and then asks us, "Okay, so what's the technical research agenda?" This is a lot of people.

what's the community in which you hope to publish this?

It doesn't matter much. It's something we would email to particular humans who are already interested.

Why is Eliezer-time measured in months, and Luke-time in hours?

See here.

Do you expect to involve folks who haven't previously been involved with SIAI? If so, when?

Possibly, e.g. domain experts in micro-econ. When we need them.

How large a research team / author list would you expect the final version to have? Is fairly large "5" or "15"?

My guess is 10-ish.