I agree completely!
"Nor does it give anyone the authority to make believing in something that cant be found or substantiated in Scripture as binding on the believer."
I substantially agree (!), but with this amendment:
"Nor does it give anyone the authority to make believing in something that is not in harmony with, or which is directly and unambiguously contrary to Scripture, as binding on the believer."
That's where the disputed questions really begin. Fortunately, we (you and I and the whole Church) are not without recourse to the Holy Spirit.
OK. Where does Scripture state that Mary was perpetually a virgin or even imply in light of the multitude of verses that refer to Jesus’ siblings?
Where does it teach at all that she was immaculately conceived? Especially in light of all the verses that address the sinfulness of man and even Mary’s own testimony that she needed a savior.
And those are only TWO examples. There are plenty others that can be addressed.