You've touched on one of the deficiencies of the article - although the priesthood of all believers and its relationship to the apostolic ministry is covered very eloquently in the catechsim section to which the article links. The article also fails to make sufficient reference to Jesus as High Priest - a grave omission for any discussion of Holy Orders.
Your translations of the terms are correct as far as they go but the next statement does not follow from those translations, nor do those translations in themselves provide any insight into how the offices were performed in the first century or how people came to be placed in those offices.
If the priesthood of all believers has a sacerdotal character (as you state) and Jesus' role as High Priest has a sacerdotal character, why would the apostolic ministry be precluded from having such a character?
To get to the point, I cannot see a priest any more “In Christi Loco” than every other believer. We are all crucified with Christ and then raised up to new life in Him. We are all commanded to forgive sins. When we reverently and faithfully consume the body and blood at the Eucharistic feast, we are all made part of Christ and He is made part of us.
Priests and bishops are not given some special gnosis of God, and the validity of a sacrament depends upon the work of the Holy Ghost, not the nature of the persons involved in the liturgy. But because sacraments are serious matters and should not be celebrated flippantly and irreverently (no comment about some of the monstrosities that are passed off as liturgies these days), the leaders of the Church (aka bishops) only permit specially trained and faithful elders (aka priests) to lead them.