I'm a magic player too and reading this thread makes me really sad. The fact that it can be against the rules to misrepresent hidden information is absolutely ridiculous. It should just be another part of the skill set that can be used to help win the game.
I understand that the game has younger players and the idea of bluffing could be detrimental to their playing (as it encourages deception and lying as a method of victory, which is not a good life lesson for an 8 year old) As well, those younger kids are more likely to think it 'cheap' or underhanded to win with a bluff and would thus take away some of the fun for them.
However, older players should be able to separate the game from reality enough to not have the idea of bluffing teach them bad life lessons.
I think that bluffing should be allowed in the masters division under the following circumstances:
1) No deception is made regarding public information. If a player asks about a card's ability or # of prizes or damage counters or cards in hand, the answer must be completely truthful. However, there should be no penalty for saying openly: "My luxray is prized, darn" as your opponent should be given the option of believing or disbelieving themselves. As the information is private, you should have no reason to have to tell the truth, but also should have nothing stopping you from a bluff.
2) Cards on the table that are not in your deck need to be a translation. There is no reason for any other card to be on the table.
3) If a player shows a card with the intent to deceive (make the opponent do it's actions without having to play it), that player should be given a warning, then a game loss. The player tricked should not be penalized but if they shuffled their hand or anything, should have to live with that.
4) Note taking within a game should be allowed, as long as it is done in a timely fashion and is done in public. such as prize location and opponents hand after an effect.
This is just my opinion but I feel it would add a next level of skill to the game