Stubborn and Desmond,
This is an interesting argument but you guys are stuck in a rut, so let's tackle this from another angle. Let's start with what we all agree on:
Unbaptised persons = not Catholic. This includes: Jews, pagans and all other religions.
Apostate = a catholic who abandons his faith totally (this does NOT include those who stop practicing their Faith, but those who turn to pagan religions, thus abandoning Christ totally).
Heretic = a catholic who rejects one or more catholic doctrines.
Schismatic = a catholic who rejects the authority of the Church (i.e. bishop(s) or Pope) in some area.
Excommunicated = a catholic who has incurred a penalty/sanction from the Church because of 1) sin of heresy or 2) sin of disobedience (he's a schismatic), or 3) sin of apostasy.
a. Ipso facto excommunication - Basically, this is "automatic" excommunication, because of the person's actions.
b. Formal excommunication - This is 'ipso facto' excommunication which has been RATIFIED by the Church, which followed the legal steps and declared the 'ipso facto' condition to be public, formal and binding.
Now, we must distinguish between the excommunication and the penalties associated with it, which vary according to canon law. Any excommunication (whether 'ipso facto' or 'formal') carries with it a spiritual penalty (i.e. the person is "cut off" from the sacraments) and this is why they are said to be "outside of the Church". In the same way that one in mortal sin is "cut off" from God and
"cut off" from heaven.
An excommunication has 2 penalities - 1) the sin involved, usually against Faith (which is why the penalites are so severe), 2) the Church's penalty, of not being able to take part in the sacraments (i.e. outside the Church).
An excomm can, and are still required, to go to Mass, but (in some extreme cases) even if they wanted to repent/confess, they would have to to wait and get a formal hearing, as some excomm can only be lifted by the Bishop, The Holy See, or the Pope himself.
But, when we speak of one's church office (being a bishop, or a cardinal, or even pope), even one who is 'ipso facto' excommunicated, does not AUTOMATICALLY lose their office. They automatically lose their state of grace, automatically lose the benefit of the sacraments but they still RETAIN THEIR OFFICE AND ITS AUTHORITY, under most circuмstances.
Let's discuss the penalties of an excomm:
A "latae sententiae" penalty (meaning by the force of the law) is incurred for all 'ipso facto' excomm. So, if you do 'a' or 'b', you've incurred the penalty. Much like when one commits a mortal sin, we've incurred the penalty of hell. It's automatic; it doesn't need to be confirmed by any authority.
The main penality for an 'ipso facto' excomm is banishment from the sacraments. Normally, it does not affect one's office or authority. This has to be confirmed by Church authorities. There are certain, extreme cases where one automatically loses his authority/office but not related to heresy.
A "ferendae sententiae" (meaning "sentence to be passed") penalty is one that binds a guilty party only after it has been imposed on the person by Church authorities.
All this being said, the question of if one "outside of the church" can hold office is not as clear cut as some of the quotes from the popes/saints seem to make it. Oftentimes, when the quote mentions a heretic or schismatic, is it speaking of a "formal" heretic or schismatic, who has received a formal, "ferendae sententiae" and therefore loses his office and authority. But, before the Church rules, a person who has received 'ipso facto' excommunication, though he be 'outside of the Church', he still retains his office, because being 'outside of the Church' refers to his spiritual situation (i.e. cannot partake of the grace of the sacraments), not that he is no longer a Catholic.