Allow me to weigh in on the matter briefly, admittedly without having read every word posted above (in fact, not most of them).
My take on the EMHCs is that there are circumstances in which they perform a necessary function. That necessity is intensified by the fact that the number of priests is declining. There are some places in which, indeed, the people think that EMHCs are a necessity, whereas priests are not. I’ll cite an example given to me by a fellow seminarian: A woman asked her bishop who was making a visit to a parish to speak with the catechists there, “Bishop, isn’t it possible to devise a way for there to be churches without priests? I mean, couldn’t we just have someone from the audience get up and do the Gospel, and distribute Communion?”
That is precisely the senitment that too often goes in tandem with a plethora of EMHCs and which is dangerous to the future of the Church. At my former parish, it was routine to schedule no less than five EMHCs at every Mass. One cannot, in my opinion, be an Extraordinary Minister of Holy Communion if you’re on a schedule. It’s more a matter of the priest saying, “Gee willikers, I don’t think I can get this all done by myself. Better have someone help me.”
The idea of having people deputed by a bishop to do this under specific circumstances has been advanced, and I do not think it would be unwise. After all, if someone is going to be performing a function Ordinarily performed by a priest, they may as well have a wee bit of training and the approval of the man responsible for such things, no?
And as for EMHCs opening the tabernacle, Francis Card. Arinze, Prefect of the Congregation for Divine Worship and the Discipline of the Sacraments, made it perfectly clear in an interview he gave to EWTN that only those who can be considered Ordinary Ministers of Holy Communion are to open the tabernacle, under normal circumstance. OMHCs would be bishops, priests, and deacons, in general.
If a priest tells me to something at Mass, his being a priest does not of necessity mean that the thing he’s asking me to do ought to be done. Exempli gratia: If a priest told me to strip down to my skivees and do the “funky chicken” after Communion, I would respectfully decline. And that is not even specifically prohibited by a law (just common sense). Much less would I do something that is specifically prohibited, such as open the tabernacle when I am not supposed to.
This attitude that whatever a priest says goes is what gave rise to Star Trek Masses and clown Masses and Rocky Horror Picture Show Masses in decades past. Priests are not infallible, and even the pope’s infallibility is limited to specific times. If you’re looking for someone whose word you can trust always, at every time, in every place, no matter what it might be, then you are looking for God. Generally, God does not direct people to do this or that little action during the Mass.
Now, I have said numerous times, “under usual circumstance” or something to that effect. What I mean, simply, is that if your priest happens to be in a wheelchair or in some other way unable to distribute Communion, I would not, myself, have a problem seeing someone else do it, though this ought to be rare and unexpected.
Hooray, Liturgical Abuse!