Thanks so much, Sunyo, that was well put.
One passage that I would add here is that of Mogharaja at Snp 5.16. Thanissaro contrasts this with the questions of Vacchagotta, saying that the Buddha answered Mogharaja’s questions, whereas he didn’t answer Vacchagotta. The difference must be that Mogharaja asked about a strategy:
How should I view the world so that the king of death does not see me?
But if you look at the text, rather than just the immediate passage quoted by Thanissaro, it begins with Mogharaja saying this:
Dvāhaṃ sakkaṃ apucchissaṃ
I have asked the Sakyan twice,
Na me byākāsi cakkhumā
and the seer has not answered me.
Vacchagotta, of course, just asked once and left. So if he had been as patient as Mogharaja, perhaps we would have been spared all this!
According to the commentary, the reason the Buddha delayed answering had nothing to do with whether it was strategic on ontological, but because when he first asked, Mogharaja was not ready. But as he sat patiently with his friends, and listened to the various questions and answers, his wisdom matured, so the Buddha answered when the time was right.
Obviously we can’t rely on this as a historical source, but it is not unreasonable. And it is basically the same reason the Buddha gave for not answering Vacchagotta: because the questioner would not have understood properly.
In addition, there is also the problem that “existence” implied “eternal existence”, which I have previously discussed in a couple of posts: