Another perfectly reasonable approach is to task the AI with nothing more than data processing with no effectors in the real world (Oracle AI), and watch it like a hawk.

I consider this semi-reasonable, and in fact, wouldn't even feel the need to watch it like a hawk. Without a decision-outputting algorithm, it's not an agent, it's just a learner: it can't possibly damage human interests.

I say "semi" reasonable, because there is still the issue of understanding debug output from the Oracle's internal knowledge representations, and putting it to some productive usage.

I also consider a proper Friendly AI to be much more "morally profitable", in the sense of yielding a much greater benefit than usage of an Oracle Learner by untrustworthy humans.

Bzzzt. Wrong. You still haven't explained how to create an agent that will faithfully implement my verbal instruction to bring me a pizza. You have a valid case in the sense of pointing out that there can easily exist a "middle ground" between the Superintelligent Artificial Ethicist (Friendly AI in its fullest sense), the Superintelligent Paper Clipper (a perverse, somewhat unlikely malprogramming of a real superintelligence), and the Reward-Button Addicted Reinforcement Learner (the easiest unfriendly AI to actually build). What you haven't shown is how to actually get around the Addicted Reinforcement Learner <i>and</i> the paper-clipper and actually build an agent that can be sent out for pizza without breaking down at all.

Your current answers seem to be, roughly, "We get around the problem by expecting future AI scientists to solve it for us." However, we are the AI scientists: if we don't figure out how to make AI deliver pizza on command, who will?