First thing to understand is this: holding views and asking questions are two separate things.
They are seperate yes but intertwined. What will i be can lead to a speculative view (eternalism, annhiliationism, rebirth, non-rebirth etc) or adopting a speculative view (rebirth) can lead to the questions what will i be? etc
With regard to views, I think it's a big mistake to regard them as fully "mine" or think of them as something fully under one's own control. We have all kinds of views built into our present makeup based on past kamma. Probably you can't help whether you "believe in" rebirth at this moment. You can't force yourself to adopt a view. But over time, we all know that our views change and develop, as we create new kamma. Views are caused and conditioned by kamma.
Of course people will have speculative views before but the Buddha taught a teaching that goes beyond such speculative views by focusing on what is (4nt) so that they
A) no longer attend unwisely (and so increase the taints)
B) can go beyond all speculative views and dukkha (and in process see how such speculative views come to be via identification)
Now im not saying it is necessarily wrong or bad to have (certain) speculative views, but the Buddhadhamma is beyond speculative views (i.e. rebirth), it doesnt include them (when i say buddhadhamma i mean his own teachings, 4nt and D.O.)
That is why the Buddha often would describe the views of an ordinary, run-of-the-mill person. My reading is that these were descriptions. I don't think the Buddha advised: Okay, now immediately change your mind and hold a different view instead! Rather, I believe the Buddha advised following the full 8fold path, thus perfecting right view as a consequence. Obviously, if we're ordinary run-of-the-mill people, we're going to have some of the not-right views that the Buddha described.
He didnt teach that to those who held speculative views but to those following his own teachings he taught the NEFP, which right/noble view/understanding is of the 4NT, i.e. appropriate attention
"He attends appropriately, This is stress... This is the origination of stress... This is the cessation of stress... This is the way leading to the cessation of stress. As he attends appropriately in this way, three fetters are abandoned in him: identity-view, doubt, and grasping at precepts & practices. These are called the fermentations to be abandoned by seeing.
And not about speculative rebirth view since this involves unwise attention
"This is how he attends inappropriately: 'Was I in the past? Was I not in the past? What was I in the past? How was I in the past? Having been what, what was I in the past? Shall I be in the future? Shall I not be in the future? What shall I be in the future? How shall I be in the future? Having been what, what shall I be in the future?' Or else he is inwardly perplexed about the immediate present: 'Am I? Am I not? What am I? How am I? Where has this being come from? Where is it bound?'
http://www.accesstoinsight.org/tipitaka ... .than.html
With regard to asking questions, I don't think there's any time when the Buddha advised: Don't ask that question. Seems to me that the Buddha encouraged inquiry. BUT the Buddha seemed to caution against dwelling on certain questions or getting stuck on them, because dwelling on those questions is counterproductive.
He never said "dont you ever ask such questions" but when people took up his teachings, he advised that its unwise to ask such questions since they lead to developing and/or strengthening the taints (and so ignorance etc and so the whole mass of dukkha)
You seem to back up my point in the last sentence
"BUT the Buddha seemed to caution against dwelling on certain questions or getting stuck on them, because dwelling on those questions is counterproductive"
He taught wise attention, a way to go beyond all such speculative, counterproductive questions that dont lead to the ending of dukkha and in fact only increase/sustain it, which rebirth view/questions does