Unfortunately, referencing the Bible to attack those who doubt and/or question teachings is easy because the books of the Bible themselves are premised on being the "Word" of God (so to question them is to "prove" you must be an apostate).
Exactly, your questions can only go so far before you're actually questioning the sacredness of the Bible itself. Most JWs will not entertain the idea for even a brief instant. The Bible's inherited authority is still very strong, especially when people are indoctrinated with the idea that only "bad" people would question the Bible. JWs also portray those who question as having ulterior motives. That they simply want to live immoral lives without being accountable to God.