Can I use Porygon-Z's "Crazy Code" Ability to attach Impact Energy to a Pokemon that isn't a Single Strike Pokemon?
Yes you can, but then it would get discarded immediately. However, if that Pokemon was Poisoned, Impact Energy would remove the Special Condition.
Source: TPCi Rules Team (2021-07-01)
Can I use Urn of Vitality to shuffle the card Impact Energy from my discard pile into my deck?
No, you cannot. Urn of Vitality is only able to target a specific card named "Single Strike Energy". Although Impact Energy is a "Single Strike" Energy card, it is not "Single Strike Energy".
Source: Chilling Reign FAQ; TPCi Rules Team (2021-06-17)
Can I use Houndoom's "Single Strike Roar" Ability to search my deck for the special energy card Impact Energy?
No, you cannot. Single Strike Roar is only able to target a specific card named "Single Strike Energy". Although Impact Energy is a "Single Strike" Energy card, it is not "Single Strike Energy".
Source: Chilling Reign FAQ; TPCi Rules Team (2021-06-17)