… I’m having a hard time with Mary. … with the idea that Mary remained sinless … and the bodily taking up to heaven at the end of her life …
I have a strong background both among Fundamentalists, and Protestant, in some respects. The Church itself is deeply imbued with Protestantism. This is deeply reflected in extant translations of scripture, today. It brings the task of Mary’s Assumption into a category of difficulty, which may not have been even remotely experienced by The Apostles, at the time of Mary’s death, but I could be very wrong about this.
The Assumption is an historical event. The Catholic Encyclopedia says, The Assumption is a conclusion drawn by The Apostle’s, when her body was not found in the sarcophagus, but you probably already know this. I suppose, that I do not understand the difficulty you have with The Assumption, but I think, that from The Apostle’s point of view, it was very clear: her body is to be in this sarcophagus. It is gone. We know Mary: the mother of our Lord, and therefore, we can assume – very easily – she is raised into heaven, by God.
Protestants have removed much of God’s greatness from their Bibles, first relegating such books into an appendix, then removing them altogether. I have come across more than one Fundamentalist minister, youth, and other to include Protestant pastors, that have little or no problem with removing Revelation, The Apocolypse, from The New Testament. It becomes a difficult task to accept God, The Father, and scriptures inspired by God, The Holy Ghost, when much of scripture is reduced to the mediocrity of our humanity. God is great. We would be as well were we to live – as Mother Teresa has said, we ought to do – to live as God lives. But since I am in the habit of assuming much, I have no real difficulty with it, but you: you work with youth. Assuming too much in your occupation, it would be a great burden: I imagine.

The site of Mary’s sarcophagus was not found with her body after three days, but her sarcophagus remained unknown in Jerusalem, more than a few centuries. We know much about it, through apocryphal writings.
I am very unfamiliar with many apocryphal writings, but some of them, were among the most popular writings of The Old Testament, only a few years before Jesus’ birth.
I like The Assumption, now, after having gone through some of these posts, because it is such a mystery completely left to human reason – rather than faith – I have no need of faith on the matter, only an assumption is needed. I find a bit of simple pleasure in this, because were I to be faced with an empty tomb, belonging to Jesus, and forced to assume, that he was taken up into heaven, well then, what of my faith, could persist without The Ressurrection? Yet given too many mysteries so poorly rooted in an ability to reason, it is a great relief, that I assume her to be so, and it is one of the last, “articles”, I believe is a good word of The Apostle’s Creed, I believe … in the resurrection of the body, and life everlasting. And as these articles go: consider the – I believe … in the communion of saints, … – the communion of saints, as a belief it might well further our ability to know such things. Yet, without communion, The Eucharist, then what communion of saints, is there, that we might enjoy?