If an opponent's attack damages my benched Pidgeot EX, can it do "Mirror Move" during my next turn and attack for the amount of damage it received while on the bench?
Yes, it can.
Source:
Evolutions FAQ (2016-11-03), TPCi Rules Team (2016-11-03)
Let's say I have Machop active with a Focus Sash attached, and my opponent's Mewtwo-EX uses "X Ball" for 360 damage with four Double Colorless Energy and a Muscle Band attached. The Focus Sash leaves Machop with 10 HP remaining. If I then use Ninja Boy to switch Machop with Pidgeot-EX and then use its "Mirror Move" attack, does Pidgeot-EX do 360 damage in return?
Yes, it would. When using Ninja Boy the amount of damage done last turn is remembered by the new Pokemon, so Mirror Move would do 360 damage to your opponent's Active Pokemon.
If my Mewtwo attacked with "Barrier" last turn, and this turn I retreat it and use Switch to make it active again, can I attack with "Barrier" again?
No. The prohibition against using Barrier if it was used last turn is not an effect, it is a Game State check. So it can't be cleared by moving Mewtwo to the bench.
Source:
Evolutions FAQ (2016-11-03), TPCi Rules Team (2016-11-03)
Due to an error in card text, Galvantula's "Double Thread" attack has been changed. The original text says, "This attack does 30 damage to 2 of your opponent's Pokémon. Also apply Weakness and Resistance for Benched Pokémon". The text has been changed to match the original intention of the attack, which is to affect only Benched Pokémon. Double Thread is updated to say, "This attack does 30 damage to 2 of your opponent's Benched Pokémon. Apply Weakness and Resistance". Effective immediately, Galvantula's "Double Thread" attack will use this updated attack text instead of the original text.
If I use Croagunk's "Poison Up" to attack the same Defending Pokemon on successive turns, does the amount of damage counters due to Poison increase? For example, the first time I use it the poisoned Defending Pokemon starts taking 3 more damage counters between turns, then if I use it again it starts taking 6 more damage counters (3+3), then 9 more damage counters (3+3+3), and so on?
Yes, each time you use Poison Up it increases the amount of poison damage by "3 more" than what the Defending Pokemon was already taking at the time of the attack.
Source:
Steam Siege FAQ (2016-08-04), TPCi Rules Team (2016-08-04)
If Bronzong with the "Metal Fortress" Ability is in play, are benched Pokemon protected from Greninja's "Shadow Stitching" attack? If so, does it also protect Pokemon that come into play on the bench during the opponent's turn?
If Bronzong is on the Bench, all benched Pokemon are protected, including ones put into play after the attack has happened (for example, Shaymin-EX's "Set Up" Ability will work in this scenario); however, the Active Pokemon is not protected, even if it goes to the Bench it will not get its Ability back. If Bronzong is Active and has its Metal Fortress shut off, the Benched Pokemon are not protected; even if it moves to the Bench, it will not get its Ability back. Finally, if Bronzong is on the Bench and becomes the Active Pokemon during your turn, it loses its Ability and the Benched Pokémon are no longer protected.
If you use Umbreon's "Shadow Drain" attack against a Pokemon with {D} weakness and a Bursting Balloon attached, what are the correct order of operations for placing and healing damage?
Umbreon's healing effect takes place within the context of the attack, so healing has to be completed before the attack is finished. Since Bursting Balloon is triggered by damage and you can't interrupt the attack's other effect (healing) to place those damage counters, you would heal Umbreon first and then place the damage counters for Bursting Balloon.
Glaceon-EX's "Crystal Ray" attack makes it immune to damage done by attacks from "Evolution Pokemon". This is a new term that means any Pokemon that is an evolution card. So a Stage 1 Frogadier brought to the Bench by "Water Duplicates" would be affected by this. Basic Pokemon and Restored Pokemon are not affected.
Source:
Fates Collide FAQ (2016-05-05), TPCi Rules Team (2016-05-05)