If I have Klefki with "Mischievous Lock" Ability active and switch or retreat it to an Iron Valiant ex with "Tachyon Bits" Ability, can I use Tachyon Bits?
Yes, when Iron Valiant ex switches in Klefki is no longer there, so Mischievous Lock does not prevent the use of Tachyon Bits.
Can Cramorant with the "Lost Provisions" Ability use an attack from a Technical Machine such as TM:Blindside for no energy cost if there are 4 cards in the Lost Zone?
Due to a localization error in the Brazilian Portuguese version of the Squawkabilly ex card (SV:Paldea Evolved, 169/193), the text of the "Grasnar e Aproveitar" Ability will be updated. The original text of this Pokémon's Ability was, "Uma vez durante o seu turno," ("Once during your turn,"). This Ability was intended to be used only on a player's first turn of the game. The Ability text must be updated to ensure that "Grasnar e Aproveitar" functions as intended, and must align with the original Japanese text. The new text for Squawkabilly ex's Ability will be, "Uma vez durante o seu primeiro turno," ("Once during your first turn,). The change will take effect immediately, and all Brazilian Portuguese versions of Squawkabilly ex (SV:Paldea Evolved, 169/193, 247/193, and 264/193) will use the updated Ability text.
Due to a localization error in the Brazilian Portuguese version of Weavile (SV:Paldea Evolved, 134/193), the text of the "Caçada Ofensiva" Ability will be updated. The original text of this Pokemon's Ability was, "...você poderá mandar 1 dos Pokémon no Banco do seu oponente..." ("...you may send 1 of your opponent's Benched Pokemon..."). The text must be updated to match the intended effect of this Ability, which must be in line with the original Japanese text. The new text for Weavile's Ability will be, "...você poderá mandar 1 dos Pokémon Básicos no Banco do seu oponente" ("...you may send 1 of your opponent's Benched Basic Pokemon..."). The change will take effect immediately, and all Brazilian Portuguese versions of Weavile (SV:Paldea Evolved, 134/193) will use the updated Ability text.
Source:
May 11, 2023 TPCi Announcements [https://www.pokemon.com/br/errata-de-weavile-escarlate-e-violeta-evolucoes-em-paldea-134-193-do-pokemon-estampas-ilustradas]; Nov 9, 2023 TPCi Rules Team
When I use Crobat's "Echoing Madness" attack, do I have to name specific cards like "Switch" or "Professor's Research" that my opponent won't be able to play?
No, you just choose the class of card, either "Item cards" or "Supporter cards". You don't name any specific cards.
Source:
Paradox Rift FAQ; TPCi Rules Team (2023-11-02)