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)
If you somehow get 4 Missing Clover back into your hand, can you play them all again a second time to take another prize card?
Yes, you can.
Source: Ultra Prism FAQ (2018-01-19), TPCi Rules Team (2018-02-01)