You have stated:
(1) That the Church has teachings that are falilble and require varying degrees of religious assent
and
(2) That the Church's teachings = the Magisterium = The Body of Christ and are therefore all infallible.
Gentlemen,
The more I read about the history and theology of the magisterium, the more I realize that it is super complex. The idea of the Magisterium itself is simple and most people readily understand it, including both of you. But, if you study the history of it, you'll realize that theologians over the last few centuries, (especially after V1) have changed, added and refined many of the definitions/labels of the terms. So it's very difficult to discuss this topic unless you define terms in the beginning. For example, I think I read somewhere that the Magisterium used to only refer to 1) extraordinary definitions and 2) authoritative ordinary & universal teachings. In other words, there was no such thing as the "ordinary, fallible" magisterium. This makes sense to me, because in prior centuries, when popes spoke of the magisterium, they were obviously speaking of authoritative, clear-cut teachings. They were NOT talking about the "ordinary, fallible" level, where the pope gives a sermon on sundays or he gives a speech at a religious conference.
Fast forward to the 1800s and the 1900s and theologians starting including ALL papal writings, sermons and lower-level synods, meetings, etc into the definition of the "ordinary/fallible" magisterium. Why they did this, I don't know. But there has been MUCH that has changed, definitionally, between the 1600s and now on this topic. This explains why you can't agree on terms.