How do you feel about priests not being allowed to marry?
I'm in favor of the celibate priesthood. Coming from a Protestant background where all the ministers were married, and some were female, this is a new thing for me.
It would not be liberating at all to have priests marry, but it would have the opposite effect. For very good reasons, Paul urges that men in the pastorate remain as he was, single, in order to be fully and undistractedly available for the work of the church (First Corinthians 7:32ff). There is always a push-me-pull-you going on between the concerns of the ministry and the needs of a family. The pressures lead to a horrible rate of divorce among Protestant ministers. The Catholics have this right, for practical reasons.
Some suggest that allowing priests to marry might solve the problem of the priest shortage. But wherever priests are allowed to marry (among Episcopalians or Orthodox) this has not been the result.
The theological reason is the stronger one: the priest stands in the place of Christ, who was single (no matter what the silly Da Vinci Code claims), whose bride is The Church, to whom the priest gives his entire self for life. In this sacramental way, marriage reflects the relationship Christ has with the Church, and the priest is the visible reminder of this.
Some Catholic-Rite groups allow marriage -- the Maronites in Lebanon/Palestine, for example. The policy of allowing Anglican and Orthodox priests who are married and become Roman Catholic to remain in the priesthood and also remain married is also a good idea.
Has the practice changed over time? Yes, especially when we see in First Timothy 3:2-5 how church bishops (Greek "presbyters") are urged, if they must be married at all, to 'be the huband of one wife' (verse 3)and be careful not to neglect family matters, given the demands of church service. At an early point, however, the Church in the west realized that caring for one's family as well as the family of God ripped men and their families apart (as verse 5 forewarned), and the sensible thing was to insist on a focused, celibate - yes, sacrificed - life in imitation of Christ.
The related question of women in the priesthood deserves a longer reply than I should give in this small space, so we'll save that for another day.
Grace and peace.