Catholic Presbyterian

In reading through Dr. Jordan's book the Sociology of the Church, I've found more questions than I have answers. Here are some of my thoughts:
Jordan asserts on page 15 that the reason the spotless lamb, Jesus, could eat with sinners and tax collectors is because they were members of the visible Church(I will simply grant him that point for times sake here, and because i think he is at least partially if not entirely correct in his assertion) even though the church was borderline apostate being run by the Sadducee's and pharisees. And the people Jesus was meeting and eating with were not excommunicated from the visible Church, and that they, the sinners, where willing at least at first to listen to what Jesus had to say. It is what Jordan than goes on to say that i find problematic to his whole illustrated principle of Catholicity and sectarianism(which he doesn't define clearly at all, as very few do) up to this point in the book. Jordan goes on to state that the people that listened to Jesus went on not to persevere in all those things and they thus excommunicated themselves. If this is the case, as i believe he is correct, what light ought this to bear on the church corporately regarding Catholicity and especially sectarianism?
Jordan up to this point in the book seem to speak of all visible bodies that profess Christ and practice the sacraments to be the Church. However since the Church is made up of real men, ordained and non-ordained, and all that is required for excommunication is not persevering in the faith that Jesus teaches, in scripture as understood and declared through his Spirit-filled Church, then how are the elders of these Churches to be considered to be duly constituted and properly installed? An excommunicated person cannot partake of the Eucharist. Surely we are not going to reason that he has the authority to celebrate the Eucharistic feast of the Lord's Supper, are we? These denominations of which Jordan speaks, many of which are have denied far more than the folks that didn't persevere in Christs teaching, are baptizing and celebrating the Eucharist week after week, yet by Jordan's implications these men have excommunicated themselves. So I ask the Question at what point does that ecclesial community become a sect(defined here as an excommunicated group, either implicitly as Jordan defines it or explicitly as declared by session, council or otherwise; that thus cannot be celebrating what they may and can not partake of nor benefit from)? Is there succession then inherently sectarian then as well if no or insignificant reconciliation is made from those previous corporately held errors? So in other words is it sectarian rather than historic apostolic succession(Defined simply biblical ordination by elders that have previously been vested in the apostolic authority by the laying on of hands and thus being duly-ordained and constituted) being conferred upon those men ordained in their communities? Bearing in mind the Church, and especially the reformed Churches have always held that only duly ordained men are permitted and actually able conduct the Lords supper. So do the excommunicants corporately, in Jordan's paradigm of Ecclesiology, fit into a sect and if so 1Cor 11 tells us that divisiveness and division that it produces is the one thing that can keep the Eucharist that they celebrated from even being the Eucharist.
So I am not finding much consistency in Jordan's application of self-excommunication and the visible Church as it stands today particularly by way of this element of Sacramentology and broader Ecclesiological principles regarding the true Church visible.

Just some ramblings I had after reading this first chapter please contribute your thoughts on the matter as well.