I described some of the implicit assumptions in a new post, as it got too long.I'll try to address the other questions:
all of the questions you posed implicitly assume one answer.
All questions are conditioned on the knowledge of the person, who is asking. The optimal answer depends on the person's knowledge and the question. I see the answer as a tool for setting the questioner's mind in a different state. I guess there might be many different answers, which can have the same effect.
They also assume that it is possible to know when a question has been answered.
Everyone has their own value function, which determines, whether the question is answered sufficiently. And of course, this value function is also conditioned on it's owner's current knowledge, which means that when the knowledge is updated, the value function can change it's output - that's when you realize that you understand nothing and you have to dig deeper.
no answer is ever final
I'll have to make another post for this.. :)
how do you actually move forward and make progress?
Well I sketched out one possibility in the OP, but I think I will have to address the question above first for it to make sense.