Interesting piece.
I would suggest that two other issues are not addressed:
Church Tradition — Catholics and Protestants see Mary and other Saints differently. Many church teachings beyond the Saints can also be considered traditional rather than scriptural. This is not a minor point.
Priesthood of all believers — again, there is a sharp distinction.
Both points could be considered areas of “intercession”. Do believers go directly to the Word and directly to Christ? Or do intermediaries play a valuable role? Can Mary intercede? Is confession to an earthly priest valuable/necessary?
The basic rift is pretty wide, IMO.
RE: Church Tradition — Catholics and Protestants see Mary and other Saints differently.
Here’s a question — is it MANDATORY for Catholics to pray to Mary and the Saints? Or is it optional?