If I used Poipole's "Knockout Reviver" attack, but then on my opponent's next turn they play Channeler, would that allow them to take a prize for KO'ing Poipole?
No, it would not. The effect of Knockout Reviver resides on Poipole, and the opponent's Channeler only clears effects on the opponent or their Pokemon.
Source: TPCi Rules Team (2019-08-22)
What happens if I play Hapu with less than 6 cards in my deck?
You would put 2 cards (or 1 if you only have 1 card in your deck) in your hand and discard the rest.
Source: Unified Minds FAQ (2019-07-19), TPCi Rules Team (2019-08-01)
If Thunder Mountain {*} is in play, does Pikachu & Zekrom GX's "Tag Bolt GX" attack need 5 {L} attached or 6 {L} attached in order to get its bonus effect?
The base energy requirement of the attack is one {L} less for Thunder Mountain {*}, but it does not apply to the additional energy required for its bonus effect. You need 5 {L} attached in order to get the bonus when Thunder Mountain {*} is in play.
Source: TPCi Rules Team (2019-08-01)
Can I use Viridian Forest if I have no cards left in my deck, and just discard a card from my hand?
Yes, you can. The first sentence of Viridian Forest says to discard a card from your hand. Then if you can do that, you do as much of the rest of the card as you can, which in this case is draw no cards.
Source: TPCi Rules Team (2019-08-01)
Could I play Blaine's Quiz Show and put down Munchlax which has no attack?
No. You can only choose to put down a Pokemon that has an attack you can declare to your opponent.
Source: Unified Minds FAQ (2019-07-19), TPCi Rules Team (2019-08-01)
If I play Blaine's Quiz Show and put down "Celebi and Venusaur GX", do I win if the opponent says "Venusaur and Celebi GX" instead?
As long as they get both Pokemon of the Tag Team correct and they include the "GX" part, you shouldn't get that nit-picky about which Pokemon is billed first.
Source: TPCi Rules Team (2019-08-01)
Say I play Blaine's Quiz Show and put Giratina Prism Star down, but my opponent just says "Giratina". Do I get 4 cards?
Yes, you do. Your opponent needs to name the full name on the card.
Source: WotC Chat (2001-01-18), TPCi Rules Team (2019-08-01)
Can I play Blue's Tactics if I have more than 8 cards in my hand?
Yes, because you could still have less than 8 cards in your hand by the end of your turn.
Source: Unified Minds FAQ (2019-07-19), TPCi Rules Team (2019-08-01)
If I use Blue's Tactics and then later KO an opponent's Pokemon, do I take prize cards and then draw until I have 8 or can I choose the order this happens in?
You take your Prize cards first, and then at the end of your turn you draw for Blue's Tactics.
Source: TPCi Rules Team (2019-08-01)