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)
If I used Steelix's "Gigaton Shake" on my previous turn, would Channeler allow my Pokemon to attack this turn?
Yes, the effect of Gigaton Shake would be removed, and your Pokemon would be able to attack.
Source: Unified Minds FAQ (2019-07-19), TPCi Rules Team (2019-08-01)
Can I use Giant Hearth if I have no cards left in my deck, and just discard a card from my hand?
Yes, you can. The first sentence of Giant Hearth 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)
If I have Focus Sash attached to Marshadow & Machamp GX and then use its "Acme of Heroism GX" attack, which one takes precedence if Marshadow & Machamp GX would be KO'd by damage from an opponent's attack?
You would choose, as they have the same effect, you choose the order of resolution.
Source: TPCi Rules Team (2019-06-27)
If I use Raichu's "Evoshock" Ability to paralyze my opponent's Active Pokemon, does the Paralyzed status condition get removed if my opponent attaches a Stealthy Hood to that Pokemon on their next turn?
The Evoshock Ability's effect is to Paralyze the opponent's Pokemon; once that Special Condition has been placed it is no longer considered an effect of the Ability at the time your opponent attaches the Stealthy Hood. Therefore, your opponent's Pokemon remains Paralyzed.
Source: TPCi Rules Team (2019-06-06)
Can you play Darkrai GX with "Restoration" Ability from your Discard Pile if Power Plant is in play? And if so, do you do all of its effects?
Since the Discard Pile is not considered "in play", Darkrai GX can use its Restoration Ability to put it onto the Bench and attach a Darkness Energy card from the Discard Pile to it. Once all of the Ability's effects are complete, then Power Plant shuts off the Ability.
Source: TPCi Rules Team (2019-06-06)