Tim Staples book "Behold Your Mother" is the best study on this you will find.
> Obviously both dogmas could be true, but my question is why are they assumed to be true, why is the church so sure that they are true, why is it so important that they must be true, that they are raised to the level of dogma.
First, for an in-depth treatment of this, I definitely recommend Behold Your Mother: A Biblical And Historical Defense Of The Marian Doctrines, by Tim Staples, and Hail, Holy Queen: The Mother Of God In The Word Of God, by Scott Hahn. Both relatively affordable if you choose the "used books" option on Amazon, and highly recommended.
To give a brief overview here... we first must recognize that every Marian dogma, and any title given to the Blessed Mother, is meant to magnify or point to some reality about Jesus Christ. The dogmas you referenced can be drawn out from the Catholic beliefs about Mary and certain biblical titles she holds - The New Eve, The Ark Of The New Covenant, The Queen Of Heaven.
If I may ask, are you able to go a bit more in depth on what specifically is challenging about each doctrine, apart from not seeing their connection with other important Christian doctrines? That might help me lend a bit more guidance apart from the books I recommended. Prayers your way!
Mary’s intercessory role is related to her queenship, which in turn is related to Christ’s kingship. Dr Brant Pitre touches on this in the following video.
Consider checking out the book by former Protestant Tim Staples, Behold Your Mother: A Biblical and Historical Defense of the Marian Doctrines https://www.amazon.com/dp/1938983912/ref=cm_sw_r_cp_api_glt_fabc_37PWBA8HMSK887DR6JK4
There are some good books you can get on kindle that would really explain the theology behind Mary
Behold Your Mother: A Biblical and Historical Defense of the Marian Doctrines https://www.amazon.com/dp/1938983912/ref=cm_sw_r_cp_api_glt_fabc_ZX0M5GEKNGNMBK92G72Y
Jesus and the Jewish Roots of Mary: Unveiling the Mother of the Messiah https://www.amazon.com/dp/0525572732/ref=cm_sw_r_cp_api_glt_fabc_69CXHNTD5598BDSS30KJ
How I love her! Our Lady of Guadalupe
A personal favorite book Our Lady of Fatima
The shortest and most compact of all the books Meet your Mother