Terrific post. Thanks for jumping in, with work right now I'm just in and out too quickly.
It seems to be an old pattern I've only recently come to recognize. Claims are made such as "Protestant beliefs have only been around since the Reformation",or "we created the Canon of Scripture" as though they are fact even though the historical record is clear that these claims are false.
Proestant beleifs are pretty uniquely western in origin and practice.
Clear? For three days I ask you to show me any historical record of Protestant beliefs approximated in the early Church. The best you have so far is that their books were burned. But no other heresy is that obscure: most early Christian writing that survives is apologetical and debates the heretics. How come nothing resembling protestantism shows up in Adversus Heresies?