If I have multiple Chesnaught V with the "Needle Line" Ability in play, will each of them put 3 damage counters on the Attacking Pokemon, or does "Needle Line" only work for the Active Chesnaught V?
Each separate Needle Line Ability will stack to add 3 more damage counters to the Attacking Pokemon, but only when the Active Chesnaught V is damaged by an attack.
Source:
Silver Tempest FAQ; TPCi Rules Team (2022-11-10)
If I have multiple Rapidash in play can I use each one of their "Heat Boost" Abilities once per turn, or do I only get to use a maximum of one "Heat Boost" per turn regardless of how many I have in play?
Each Rapidash can use its own Heat Boost during the turn, but only one time each. And when you use Heat Boost multiple times you have to discard a separate {R} Energy card for each one and your {R} Pokemon's attacks do +30 more damage per Ability used.
Source:
Silver Tempest FAQ; TPCi Rules Team (2022-11-10)
When Radiant Jirachi is Knocked Out by damage from an opponent's attack, using its "Entrusted Wishes" Ability is mandatory. You must search your deck, and you must take at least 1 card if you are able to.
Source:
Silver Tempest FAQ; TPCi Rules Team (2022-11-10)
If I have Virizion V with "Verdant Wind" Ability in play, can I play Spicy Seasoned Curry to heal 40 damage from one of my Pokemon with {G} Energy attached and not get Burned?
Yes that would work, even if there's no damage on the Pokemon with {G} Energy attached. It's a valid target to be Burned, but the Burn condition is blocked by Verdant Wind.
When I try to attack, does Marowak's "Bodyguard" Ability prevent me from having to flip a coin if my active Pokemon was attacked last turn with Silicobra's "Sand Attack"?
The effect of Sand Attack is on your Pokemon that was attacked, not on you. So, Bodyguard does not prevent you from having to flip a coin to see if the attack goes through
Can I use Comfey's "Flower Selecting" Ability or Colress's Experiment if I have only 1 card left in my deck?
You can play either of them with only one card left in your deck; but you have to put the card into your hand, you cannot discard it or put it into the Lost Zone.
If my opponent has an Empoleon V with "Emperor's Eyes" Ability active, and I have both an Eevee with a Memory Capsule attached and an Eevee with the "Resonant Evolution" Ability in play, if I evolve the Eevee with a Memory Capsule into a Jolteon with "Thunderous Awakening" Ability can I use "Resonant Evolution" or not?
Yes, that will work because Emperor's Eyes has been disabled.