My two cents:
1. "My question to you is: is this Marian doctrine of Mary as co-redemptrix/co-mediary in the catechism? Is this officially considered as a standard teaching or only held by certain pockets in the church?"
I understand that is not, and that the current Pope does not like it because it seems like putting Mary in the level of Jesus and makes ecumenism more difficult. In fact I heard some people have allready being reprimanded for teaching that.
2.About the birth control issue. That is the doctrine of the Church I have most trouble with. I think modern like makes some forms of artificial birth control necessary.
But the Church is in that issue being more Biblical that even most Prostestants are. Remember until the 1930s all Christian Churches did not like birth control too.
The problem is that the Bible has a pattern of condemming all non reproductive use of sex as sin against hollyness. That is shown in the fact that the Bible does condemm masturbation and homosexuality. Both cases sex is done without a reproductive mission. And the Early Church Fathers, in their polemics with gnostic heretics and pagans made clear that taking herbs or using condons to avoid having children was a sin. So the Church is being honest in that. You cannot state for nearly 2000 that separating sex from human reproduction is bad and them say "Oh, is not longer bad anymore", as other churches had done. If you say that birth control is OK, why masturbation and homosexuality are bad? The liberal protestant teachings and the Catholic Church teachings are coherent here. If birth control is OK, gay sex is OK as the liberals teach. The Catholic Church teaches both are bad because they are sins against hollyness and will lead you to selfindulgence.
Personaly I thing that the CC should relax their teaching, making ABC a venial sin between married couples and allowing medical reasons for their use. But I the CC relaxes completely their teaching on ABC, it makes all the teaching on sexual sin seem as a huge practical joke. That is that other conservative Christians had not realized.
3. The Saints. One problem protestants have is that their Bibles had several books missing. Praying to the saints and for the angels is a doctrine contained in those books and confirmed in Revelations. Is not different that when you ask somebody living in earth to pray for you. The saints in heaven also pray for you. BTW I have seen in a movie about ultraorthodox hasidic Jews, a woman pray to Yahweh and mention in her prayer that she directs the prayer with the name of a famous Rabbi that lived in Prague, so some jews do something similar. But as a Hispanic, I understand why the OP is squeamish. Some Hispanics do abuse the practice specially those who are in synchretism with Santeria.
4. About the patricarchy in the Catholic Church, personally I found conservative protestants more patriarchal than Catholics. Yes, unlike liberal protestants from the 1960s onward the CC does not order women.
But for centuries the CC had providend strong role models for christian women and women had a strong indirect influence on church affairs. Starting with Mary the mother of Jesus, St Monica, Hidlegaard of Bingen, Julianna of Norwich, Elisabeth of Hungary, Joanne D'Arc, Catherinna of Sienna, Teresa de Avila, Rosa de Lima, Therese of Liseaux, Gemma Galgani, Mother Theresa of Calcutta, the Sister of Mercy (several saints there, like Sor Faustina) , Dorothy Day, Edith Stein, Simone Weil, Sor Ines de la Cruz and many more.
A Catholic woman looking for role models has plenty to look up.
