When using Slowking's "Opponent's Choice" Poke-POWER, do you have to show your opponent what the cards are since it says 'you may reveal the top 2 cards'?
Of course you have to show the opponent what the cards are. The "you may" refers to using the power, not to being able to use it without showing them the cards.
Source:
Undaunted FAQ (2010-09-09), PUI Rules Team (2010-09-09)
When I use Shaymin's "Celebration Wind" Poke-POWER, can I move my energy cards in play around to any and all of my Pokemon that I want, or just to one Pokemon?
You can move the energy cards from more than one Pokemon and move them to more than one Pokemon, as desired. However, once you have taken another action, like playing a Pokemon card onto your bench, attaching an energy card from your hand, retreating your Active Pokemon, etc. you can no longer move any energy cards around.
Source:
Unleashed FAQ (2010-05-13), PUI Rules Team (2010-05-13)
Three cards have been added to the list of errata for the Pokémon Trading Card Game. [...] The text below reflects what the card should say, not what was originally printed. "When you attach an Energy card from your hand to Onix, remove a damage counter from Onix." This Poké-Body only works when you attach an Energy card to Onix.
Source:
PUI Rules Team (2010-05-06), TPCi Errata Update (2010-05-07)
Can I use Ninetales' "Roast Reveal" Poke-POWER when I have no cards in my deck?
Yes, you do as much of the power as you are able; discard 1 Fire Energy card from your hand, then the Poke-POWER's effect ends, without drawing any cards.
Source:
HeartGold & SoulSilver FAQ (2010-02-11), PUI Rules Team (2010-02-11)