That is your interpretation.
It is a tradition of man.
No, it is a voluntary vow taken by men who want to become priests.
Can a married man become a priest. A man not already ordained by another church, but a married laity become a priest? If not, why? The Scripture is very clear about how a priest of the Church should treat his wife. I would take that to mean the Scripture is fine with a priest being married.
Can a man who wants to become a priest and who doesn't want to make a voluntary vow on your celibacy rule still become a priest??? If not, it is then not voluntary...It's a requirement...