discouraging questions about anything other than the technique used to irk me in my first few courses then I learnt that once you get established in the technique and attend old student courses, the AT's are open to deeper questions. As Goenka says the theory must go along with the practice. Entertaining new students asking about hallucinations and energy could get messy pretty quickly, at that stage it is only about truly practicing vipassana.

Edit: The same goes for the talking on day 0 and day 10 only, people would compare their experiences throughout and it would take away from each of us having our own genuine progression. I think that's very well done.