Can you use Manaphy's "Pulling Currents" attack when your opponent has a full bench?
It's public knowledge that you can't put down any additional Basic Pokemon on your opponent's full Bench, so although the attack can be used you cannot look at your opponent's hand and you cannot put any additional Basic Pokemon on your opponent's Bench.
If my opponent has Duraludon VMAX with the "Skyscraper" Ability in play, when I use Inteleon VMAX's "G-Max Spiral" attack and choose to return the only Special Energy card attached to Inteleon VMAX to my hand, does "Skyscraper" prevent the damage or not?
The choice to remove the Special Energy card is made first, but then damage is done and finally effects of the attack. So removing the Special Energy card is an effect that doesn't happen until damage has been done and therefore blocked by Skyscraper.
If my Lumineon V attacks with "Aqua Return" to take my last prize card, but Lumineon V is my only Pokemon in play, do I win because I took my last prize before shuffling Lumineon V into my deck or do I lose because Lumineon V get shuffled in before taking my last prize?
Everything has to resolve before you check for win conditions, and in this scenario both players have achieved one win condition; the game would then be resolved by either Sudden Death or a Tiebreaker Game. However, if the opponent also has no remaining Benched Pokemon then they would lose due to 2 win conditions vs. only 1!
If I have 6 cards in my hand and use Mimikyu's "Impersonation" attack to discard Erika's Hospitality from my hand, can I use the effect of Erika's Hospitality?
Since you have 5 cards in your hand after discarding the Erika's Hospitality you can use its effect.
If my opponent's Florges used its "Moonblast" attack last turn, would my Kilowattrel's "Skill Dive" attack only do 20 damage to a Benched Pokemon?
Yes, all attack damage is reduced by 30. This damage reduction applies to all Defending Pokemon (including Benched Pokemon), and also applies to any self-damage done to your own Pokemon.
Source:
Scarlet & Violet FAQ; TPCi Rules Team (2023-03-30)