You are right, of course. But I think there are a few questions that rebel could still ask, and she might not be seen in a bad light.
For example: Do you know what blood factors you are allowed to take? Have you thought about whether you would take them?
These questions are loaded with potential negative impact to the WTS, but they are very legitimate. They force independent thinking and they are especially damning to the WTS because they force a person to realize he has a conscience that might not be dictated in all cases by the WTS. Therefore, that question can really be a key to freedom.
Another: Can a member of the faithful and discreet slave question a current policy of the WTS? This one is admittedly too loaded to be used verbatim. But it could be brought up if another conversation created a context for it. Carl Olaf Johnnson wanted to remain a JW but was slandered and pushed away only because he questioned the 607/1914 doctrine. He hadn't published anything yet. He just sent his research to the WTS. But what if the question had come from an accepted member of the remnant, which makes them a part of that FDS?
A more subtle way to ask that question is: Are the members of the Writing Department who write study articles for the Watchtower all part of the FDS? What about the other articles? What about Book Study books?
The answer is currently no, they are not. But even if the JW doesn't know for sure about the answer, the question is loaded with subtle hints about the levels of authority found in the publications. (The implication is that maybe you don't need an FDS for the Awake, but probably should have one for a Watchtower study article.
I think we should take advantage of asking JWs this question before they change the definition of the FDS. If the question gets asked enough now, it will have more impact if and when a change to the doctrine actually happens. The change to the definition of "generation" was a predicted among apostates long before Nov 1 1995. This could have been a bigger embarrassment if it had been published.
The "FDS" doctrine is the only current doctrine that provides the WTS any "official" authority over JWs. In about 20 years, that doctrine will make even less sense when it will be obvious that no members of either Writing or GB were part of the original calling of "anointed" that once ended in 1881, then later in 1918, then only "the exceptional replacement" after 1935. By 2025 anyone not over 100 years old would have been a "replacement" FDS. This will bring up a subtle problem. How faithful and discreet were the chosen FDS if we are now (2025) working with a "replacement" team? How authoritative, therefore, were the orignal FDS? There are holes in the argument, but it still has an effect.
My guess is that they either need to shift emphasis to a new prophecy outside the FDS "prophecy" or they need to have a QFR: Some of the brothers have asked how the FDS are actually feeding us spiritual "food at the proper time" when so few members of the "slave" class actually work in the Writing Department or serve on the Governing Body. For fun, I'll try to work on their "predictable" answer in another thread.