He was born in England, kidnapped by the Irish, escaped, and returned there to preach the Gospel. His followers evangelized europe, in spite of Gregory's attempts to stop them. You are the one who mistakenly believes that Rome has authority to alter scripture.
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.