As I understand it, "learn programming" is essential for working in pretty much every sub-field of computer science.

The stuff Nick Bostrom has done is generally put into the category machine ethics. (Note that this is seen as a sub-field of philosophy rather than computer science.)

I don't know much about the AGI community beyond a few hours of Googling. My understanding is that there are a handful of AGI journals, the largest and most mainstream being this one. Then there are independent AGI projects, which are sometimes looked down upon for being hopelessly optimistic. I don't know where you should begin learning about the field--I suppose Wikipedia is as good a place as any.