New to the board, so hope this is taken as trying to be helpful.
I realize there hasn't been much said on this lately, but since you were looking for more input:
In my opinion, your wording makes it less clear and I feel that the current rules are better.
You say that everyone turning their hands over can induce a player to fold prematurely. If all cards have to be turned face up, I'm not sure how this can happen. With the current rule, all players must turn their cards over. You are saying that all players have to turn their cards face up, but someone is folding prematurely? You see the contradiction? They can't fold prematurely if all cards must be turned face up. If players are being allowed to fold, that's wrong and you need to make sure that everyone (players, floor, dealers) understands that when someone is all in and betting action is complete that all cards must be turned over even if the player is certain that they have a losing hand.
Here are some comments on your changes:
At the very least, you need to clarify that this is only for all-in situations, you don't do that in 9.1
In 9.1, you don't specify anything regarding all-in or not. Reading this would indicate that all players still in the hand at the showdown must turn over their hands, whether anyone is all in or not.
In 9.2, you don't mention that betting action must be complete. As written, this would indicate that the player who is deciding whether or not to call an all in bet gets to see the cards before they have to make a decision. I realize this wouldn't be allowed, but if you are trying to make things clearer, this needs to be specified.
In 9.3, when you say "all-in players still have an obligation ..." did you mean to say all players? As written, it seems like someone will be allowed to discard a hand face-down when they are involved in a side pot prior to the pot being contested by the all-in player.
In general, it seems like you are trying to get people to only turn over their hands when the smallest side pot (latest side pot created) which they might have a piece of is going to be awarded. I don't think that is necessary, but if that is what you want, I think there are better ways of doing it. Possibly as follows, although how to word it is still going to be confusing no matter how you do it.
9.1 When there is no side pot, all cards will be turned face up once a player is all-in and all betting action is complete.
9.2 When there is one (or more) side pot(s), cards will be turned over as players are involved in the side pot which is being awarded.