So, why in poker, when an unusual situation arises, would we not allow the player to ask what his options are?
I guess the main argument is that players are expected to know the rules of the game, and that if they don't know what the rules are, the TD should not intervene by doing something that puts a player that
does know what the rules are at a disadvantage or that would potentially influence the natural outcome of the hand in some way.
One could also argue that describing the options essentially violates the one-player-to-a-hand rule, because it is not up to the TD or dealer to coach the players on how certain rules are to be applied during a hand (much like whether a TD/dealer should remind players not to muck if they wish to play the board because of the corresponding rule, or answer a question such as "if our two hands are tied, do suits play?" in the middle of the hand).
Scenario 1 is often used as a classic example. It is A's turn to act. In this case, the other players left in the hand have not really done anything wrong or unusual. The only question is whether A knows or ought to know that the betting is not reopened when action returns to him, according to the Rules. Arguably, it is up to A to know what constitutes a legal raise. It has been argued that A should be given the chance to voluntarily go all-in here for example, without the TD/dealer intervening
in advance by saying "you can only call or fold". That additional information (i.e. that A attempted to go all-in) would then be available to B & C to consider and use at their own discretion. Had the TD intervened in advance by saying you can only call, B & C would never have the opportunity to see if A would have went all-in thinking that it was still possible to do so, and thus the TD could have been considered to have interfered in the play of the hand.
I personally see the merit of not giving A any additional information in Scenario 1, although I struggle to remember exactly where I picked this approach up from. Scenario 2 is a bit different because B's OOT action is actually a direct cause of an unusual situation, so it could be argued that it is fair to inform the player of his options in the interest of fairness (especially if B's OOT action is known to be deliberate); on the other hand, should a player be expected to know what the rules say about actions out-of-turn or not?
I guess it comes down to your philosophy as to whether you think "ignorance of the law [or Rules]" so to speak, should be an excuse. I have no issues generally with players asking questions on the Rules before or after a hand, but during a hand with future action still possible, I am much less keen.