Time is a very important consideration when it comes to having a broadcast AMA, pretty much one hour it seems for most. The nice thing about the questions being from a block chain there is a record, and people can see if it was a balanced approach to the questions. I know that some of the questions will just be from those against who ever is having the AMA, but like you said and I have said, it is pretty easy to see both sides, bad questions and cherry picking all the questions. Most I have seen seem to be honest AMA's, but that trend could shift.