Why would the earliest Church liturgies call Mary a virgin if she had other children? She would no longer be called a virgin. The fact that the Church defends this doctrine, calling it infallible, says something about the deeper meaning of Mary's ever-virginity that goes beyond what lies on the surface. To an uninitiated, to one unfamiliar with the mysteries of the faith, Mary's virginity or lack thereof has little meaning. This explains why you argue against it so much - you don't understand its deeper meaning. However, to help you, think of Mary and the Church itself as interwoven. What is said about Mary in Scripture can be said about the Church theologically. The two are used interchangeably by the Church Fathers interpreting Sacred Scripture. Thus, what we say about Mary reflects not only Christology, but Ecclesiology as well.
It wouldn't do to say that the Church is not the Virgin bride of Christ. The faith is a web. Be careful of removing what you don't agree with or understand, as it effects our beliefs on other subjects.
Regards
By my thinking, the point of calling Mary a virgin was that she was still a virgin when she gave birth to Christ. This truly required a miracle, and I think we agree that it did really happen. Whether she remained a virgin after that is a fair matter for debate, but I do not think it takes anything away from Mary to believe she later had children in the conventional sense. It's a separate issue.
To an uninitiated, to one unfamiliar with the mysteries of the faith, Mary's virginity or lack thereof has little meaning. This explains why you argue against it so much - you don't understand its deeper meaning.
To me, her virginity has the meaning of a full-blown miracle. It has very high meaning.
However, to help you, think of Mary and the Church itself as interwoven. What is said about Mary in Scripture can be said about the Church theologically. The two are used interchangeably by the Church Fathers interpreting Sacred Scripture. Thus, what we say about Mary reflects not only Christology, but Ecclesiology as well.
I'm afraid that the scriptures do not reveal to me any intertwining among Mary and God's Church in the sense I think you are suggesting. They tell me that she was a great woman in Biblical history and that her faith was pure when it counted. She remains an outstanding role model, especially for women. One reason I can't reach the Roman Catholic level of veneration for her is that she got so little ink, as it were.
I hope that you and your family had a wonderful and blessed Christmas. :)