It is true that the Lord's supper passage in 1 Cor. 11 is in the context of the Chruch being one body. It establishes indeed that the Sacrfiice of the Mass is necessarily a community-building sacrament, one that defines the body of the Catholic Church as it exists in the local parish. However it does so precisely because there is a sacrifice of Christ that is at the center of the sacrament. It "shows the death of Jesus", -- it is, therefore, a sacrament rather than a memorial meal. It then is scripturally without warrant to read the phrase "discerning the body" as referring to the body of the believers. The immediate context is death of Jesus; the immediate scriptural reference is the words of consecration, "this is my body", in the synoptic gospels, that St. Paul repeats. The "body" of 1 Cor. 11:29 is then that very body shown the disciples in the appearance of bread: Jesus's.
This passage is not fully understood unless the doctrine of the real presence is understood, most fully taught in John 6.
Nay, your affirmation that it is a community-building sacrament is consistent with the interpretation you deny, as you must, to replace it with one that is based upon supposing that “this” means “turned into” rather than “represents.”
However, as said before, the latter of which is what the immediate and larger context and allegorical use of eating/drinking most warrants, rather than having normally inquisitive apostles simply drinking blood, without a word of explanation for such a novel, radical miracle, and which they had to understand was such in order for it to be efficacious.
And in which believers sppdly receive life in them by literally eating and drinking a cup, which they must continually do, rather than the Scripturally proven means of believing the gospel and becoming born again before ever eating anything.
And which, unlike what RCs overall daily show by eating the wafer and drinking the cup, results in manifest change. And who live that life out as Jesus did, by the scriptures, (Mt. 4:4) which was Jesus example of how to live by eating him in Jn. 6:57, and the doing of which was His “bread.”(Jn. 4:34)
Rather than go one and explain this more, as has been done, it is obvious you cannot even consider any other explanation so i must leave you to Rome’s ritual and its developed doctrine.