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)
If my opponent has used Latios GX's "Clear Vision GX" attack, do I get to draw 7 cards if I use Hala?
If you already used your GX Attack before Clear Vision GX, then yes you get to draw 7 cards for Hala. Otherwise no, getting hit by Clear Vision GX doesn't mean you have used your GX attack for the game.
Source: Unified Minds FAQ (2019-07-19), TPCi Rules Team (2019-08-01), TPCi Rules Team (2019-08-29)
Does Gengar & Mimikyu GX's "Horror House GX" attack prevent me from using Viridian Forest?
No, it does not. Discarding a card from your hand is not the same as playing a card from your hand; the card goes to the discard pile, not "in play".
Source: TPCi Rules Team (2019-08-22)
Can you use the "Dedechange" Ability when you play Dedenne GX from your hand while Power Plant is in play?
No, you cannot. Dedechange does not activate until Dedenne GX is on the Bench, at which time it is considered "in play" and therefore blocked by Power Plant.
Source: TPCi Rules Team (2019-08-22)
Can you use Dusk Stone to evolve directly from Litwick to Chandelure, or from Honedge directly to Aegislash?
No, because Chandelure & Aegislash (Stage 2) do not evolve from Litwick or Honedge (Basic); but you could use Dusk Stone to evolve them from Lampent or Doublade.
Source: TPCi Rules Team (2019-08-22)
Can you use Greninja GX's "Elusive Master" Ability while Power Plant is in play?
Yes, you can. You get to put Greninja GX onto your bench AND draw three cards because Elusive Master activates while it is in your hand before it comes into play, and therefore is not blocked by Power Plant.
Source: TPCi Rules Team (2019-08-22)