Can I play Erika if both I and my opponent decide not to draw any cards?
Yes, because it is not known by you or the game whether your opponent will draw cards or not.
Source: Cosmic Eclipse FAQ (2019-10-18), TPCi Rules Team (2019-10-31)
If my opponent used Magnemite's "Mirror Shot" attack last turn, can I use the effect of Will to choose heads for the effect of the attack?
Yes, that is considered an effect of an attack, so that works.
Source: Cosmic Eclipse FAQ (2019-10-18), TPCi Rules Team (2019-10-31)
When I play Guzma & Hala, after I search my deck for a Stadium, do I have to shuffle first if I'm also going to search for Special Energy and a Tool?
You can skip the shuffling after the Stadium search as long as you clearly tell your opponent you're doing the second part of the card. So if you're doing both parts you first discard two cards from your hand, then search for any Stadium you're going to take, then search for the Tool and Special Energy, then shuffle your deck.
Source: Cosmic Eclipse FAQ (2019-10-18), TPCi Rules Team (2019-10-31)
If my Pokemon is Confused, can I use the effect of Will to choose Heads for the Special Condition?
No, that isn't something that Will can affect.
Source: Cosmic Eclipse FAQ (2019-10-18), TPCi Rules Team (2019-10-31)
When I play Guzma & Hala, can I discard the Stadium I searched for as one of the 2 cards discarded to search for the Tool and Special Energy?
If you want to do the second effect you have to discard 2 cards "when you play this card", that is before you search for the Stadium.
Source: Cosmic Eclipse FAQ (2019-10-18), TPCi Rules Team (2019-10-31)
You can do any part of Guzma & Hala as long as there's at least 1 card in your deck.
Source: Cosmic Eclipse FAQ (2019-10-18), TPCi Rules Team (2019-10-31)
Can I use Sabrina's Suggestion to copy an opponent's Green's Exploration in their hand if I have a Pokemon in play with Abilities?
Nope sorry, you still have to obey the restrictions on the copied Trainer card. Since you have a Pokemon with Abilities in play you cannot use Green's Exploration even from your opponent's hand.
Source: TPCi Rules Team (2019-09-12)
Let's say I have two copies of Garchomp & Giratina GX in play, and one of them has a Double Dragon Energy and a basic Psychic Energy card attached to it. If I play Tag Switch, am I able to select only one of the Energy being provided by Double Dragon Energy, so that I may also move the Psychic Energy too? Or if I had two Double Dragon Energy cards attached, could I pick one Energy from each Double Dragon Energy for Tag Switch and move both cards?
Yes, you can either select 1 Energy from each Double Dragon Energy to move both cards, or you could select 2 Energy from one Double Dragon Energy to move just one card.
Source: TPCi Rules Team (2019-09-12)
If my opponent used Latios GX's "Clear Vision GX" attack on me, could I use Bonnie to allow my Zygarde-GX to use its GX attack?
No, you cannot. Although Bonnie would normally let Zygarde-GX re-use its GX attack, the effect of Clear Vision GX is on Zygarde-GX and that still prevents using *ANY* GX attacks.
Source: TPCi Rules Team (2019-09-05)
If my opponent used Latios GX's "Clear Vision GX" attack on me, could I use Channeler to remove that effect?
Yes you could, because Channeler removes effects from both you and your Pokemon.
Source: TPCi Rules Team (2019-08-01), TPCi Rules Team (2019-09-05)