I still don't think it's correct to say apostolic succession is broken.
It is since you do not have a valid Pope since the western schism.
So Roman Catholicism and Orthodoxy are on the same level, then. They both have severe logical flaws, so I might as well be in one as the other.
Not really since we Orthodoxs are not in contradiction, but Vatican I is in contradiction with those facts.
Several of them explicitly deny that it is possible for the bishop of Rome to promote heresy, and the rest imply it. I would certainly agree that not every exercise of papal authority falls under that, like the papal reservation of the authority to appoint bishops, but it certainly includes infallibility.
I do not agree, and oecumenical councils neither.
In what way were any of them not in communion with Rome?
There was a schism in Antioch, Rome chose to commune with the wrong bishop. Wich could be called a partial communion, but wich is not possible in the Vatican I paradigm.
The point of the Catholic dogma on councils is not that the pope needs to call them (after all, he certainly didn't call Nicea)
So a Council made of bishops not in communion with Rome can be oecumenical? Weird since Vatican I says:
"Wherefore we teach and declare that,
Both clergy and faithful,
of whatever rite and dignity,
both singly and collectively,
are bound to submit to this power by the duty of hierarchical subordination and true obedience, and this
not only in matters concerning faith and morals,
but also in those which regard the discipline and government of the church throughout the world."http://www.papalencyclicals.net/Councils/ecum20.htm#Chapter
3. On the power and character of the primacy of the Roman pontiff
St Meletius didnt seem to have known any of this.
It is required that he clearly be speaking to all and in his capacity as head of the church, and the fact that it was a private letter, as well as the uncertain tone of his whole letter to Sergius, indicates that he is not speaking as Pontifex Maximus, simply as a theologian.
Not very important since all your concepts of ex cathedra etc were not known at that time and you cant give us a list of ex cathedra statements. There are even debates about Vatican II documents, John Paul II statements etc.
Interestingly, I was referring to a non-Catholic historian, Philip Schaff, in countering your argument (http://www.ccel.org/s/schaff/history/4_ch05.htm). Fr. Dvornik is not uncontested by Catholics either.
We can both agree that Schaff is outdated on this issue. As far as Dvornik is concerned, his arguments must be answered, and not with 19th century polemical litterature.
If what you say is true, then despite my best attempts I was still led into heresy. How do I know that I won't be led there again by choosing (say) the New Calendarist Orthodox over the Old, or the Eastern over the Oriental?
Well it is like choosing a wife, you can never be sure at 100%, but it is our Faith, from studies and prayers. Of course there is always a part of personnal opinion and judgment, but i'm confident in my choice(i'm a convert to Orthodoxy).
I want to show why i'm 100% confident that RC position is untenable:
Vatican I said:That apostolic primacy which the Roman pontiff possesses as successor of Peter, the prince of the apostles, includes also the supreme power of teaching.
This holy see has always maintained this,
the constant custom of the church demonstrates it, and
the ecumenical councils, particularly those in which East and West met in the union of faith and charity, have declared it.http://www.papalencyclicals.net/Councils/ecum20.htm#Chapter
4. On the infallible teaching authority of the Roman pontiff
But as posted earlier, Fathers of the 5th oecumenical council said:
"But we bishops answered him (Pope Vigilius): "If your blessedness is willing to meet together with us and the holy Patriarchs, and the most religious bishops, and to treat of the Three Chapters and to give, in unison with us all, a suitable form of the orthodox faith, as the Holy Apostles and the holy Fathers and the four councils have done
, we will hold thee as our head, as a father and primate."
Either Vatican I is wrong, or the text of the 5th council is wrong, but they can not be both right. But, since Vatican I pretends to find its legitimacy partialy in this 5th Council, that means Vatican I is wrong. If Vatican I is wrong, then the RC can not be the true Church.
Now you only have to look for the OO, EO(not new vs old calendar since the Serb Church is old calendar, Romanian Church is new and both are in communion).