If Path to the Peak is in play and I play four Missing Clover to take a Jirachi {*} from my face down prizes, will I be able to use its "Wish Upon a Star" Ability?
Yes, you may. You are taking a Prize Card and the Ability is activated before it is in the hand or in play, so Path to the Peak does not stop it.
Source: TPCi Rules Team (2021-11-18)
What happens with Jirachi {*}'s "Wish Upon a Star" Ability if Garbodor's "Garbotoxin" Ability or "Hex Maniac" are active?
Jirachi (*) is never in the zones mentioned by those cards when you use its Ability, so Wish Upon a Star will work.
Source: TPCi Rules Team (2018-08-02)
What do I do with Jirachi {*}'s "Wish Upon a Star" Ability if my bench is full?
If you cannot put Jirachi {*} onto the bench, you just put it into your hand but do not draw another prize.
Source: Celestial Storm FAQ (2018-07-20), TPCi Rules Team (2018-08-02)
If I use Gladion and choose to put Jirachi {*} into my hand, can I use Jirachi {*}'s "Wish Upon a Star" Ability?
Sorry, but Wish Upon a Star only triggers when you are taking it as a face-down prize card, not when you are trading it with another card.
Source: TPCi Rules Team (2018-08-02)