All of the stuff you said regarding his life, of course, is true. But that does not make him an Anglican from a religious perspective.
Neither I nor Rome ever believes nor claims to have the authority to change Scripture. The Church is the custodian and servant of Scripture and Tradition, not its master. But we do have a living Church.
Please cite a reputable historical source that shows that St. Patrick was a member of the Church of England, outside the authority of the one, true, catholic and apostolic Church.
This should be interesting.
Please cite a reputable historical source that shows that Clementine understood himself to be bishop of the world. Noone is claiming that Patrick would have used the term "Anglican" to describe himself. What is being claimed is that Rome, not England, broke communion with the Church Eternal.