I am not a expert on any of the issues, but I am a reasonably well informed layperson and I know that just about every claim made about "the faith one delivered" is contestable. Similarly, just about every statement about the true nature of Anglicanism is also contestable. I am bold enough, however, to make the following observations.
First, in the 1789 Preface to the American Book of Common Prayer, the indebtedness of this Church to the Church of England is acknowledged. It is also stated that "this Church is far from intending to depart from the Church of England in any essential point of of doctrine, discipline, or worship; or further than local circumstances require. This preface has been reprinted in every successive revision of the prayer book up through the latest revision in 1979. From this, I take it that we can look at the history of the Church of England before 1789 to gain an idea of what constitutes Anglicanism.
Second, in Article Thirty Seven of the original Thirty Nine Articles, is the sentence "The Bishop of Rome hath no jurisdiction in this Realm of England." Note that the title of Article Thirty Seven is "Of the Power of the Civil Magistrates," and that it begins "The King's Majesty hath the chief power in this Realm of England." Since the articles deal elsewhere specific doctrinal issues, it's clear to me that the thrust of the sentence on the Bishop of Rome is to underline the national character of the Church of England -- the fact that it is autocephalous, if you will. And if the Church of England is autocephalous, so to is the Scottish Episcopal Church, the (US) Episcopal Church, and indeed all of the churches in the Anglican Communion.
Third, along with autocephaly, the Church of England, under Elizabeth I and her successors, exhibited both comprehensiveness and controversy. I think it's fair to say that Anglicanism characteristically treats a wide range fo theological and doctrinal differences as adiaphora -- things indifferent and not central to the faith.
Fourth, the claim of the schismatics, like Bishop Duncan, that the Episcopal Church has fallen into apostasy is just rhetoric, and warmed over, if superheated, rhetoric at that. The evidence they adduce is either a kind of inverted proof-texting from sound bites of utterances by, say, the Presiding Bishop, or the citation of various "clobber" passages from scripture. The problem is, that the issues they allege are matters for serious debate within the church, and they have prejudged the questions and avoided the debate.
Finally, as to the deposition of Bishop Duncan, I see a number of topics for consideration:
- Deposition is merely removal from office -- namely that of Bishop of the (Episcopal) Diocese of Pittsburgh
- "Abandoning the communion of this church" means the Episopal Church -- what some of the schismatics call, sneeringly but correctly, "the General Convention Church." It is a juridical, not necessarily a theological abandonment.
- The canonical question as to whether the House of Bishops acted properly was resolved in the only way possible under our polity -- by a vote of the bishops. To be sure, this is a circular process, but it's the only one we have.
- The factual question as to whether it was necessary to wait for a definitive action by Bishop Duncan was resolved, as one bishop wrote, by deciding to take Bishop Duncan at his word as to his intentions. Subsequent events demonstrate, unquestionably, that indeed he is as good as his word.