Breaking bread in the New Testament is about eating a meal not about having communion.
Genesis 14:18 does not say this was a sacrifice. It was a normal tradition to greet a guest with bread and wine. You make associations where there are none and that is called eisegeting. Same goes with Hebrew 7. What it is doing is demonstrating the fact that the Levitical priesthood is no longer applicable under the New Covenant and that Jesus is our only priest. In fact, Melchizedek was a physical manifestation of the Word of God in Genesis 14. Jesus was/is that WORD incarnate. It has nothing to do with communion, despite your attempt to make it so.
Again you're looking with your physical eyes and not your spiritual eyes. Jesus was comparing physical food with spiritual food. Obviously the physical food didn't keep them from dying, but Jesus as our spiritual food gives us eternal life. Celebrating that fact doesn't mean we actually eat food. Having him as our Savior is how we assimilate him into our lives and how we inherit eternal life. Your constant attempt to make the spiritual reality a physical one is why you keep failing at associating what Jesus was actually saying. Celebrating the example of communion he set for us at the Last Supper is exactly what he wants is to you.
Doesn't really matter what some Greek said in the latter part of the second century and how he did not understand Christian communion. It matters only with the Bible and what Jesus said about it. In that regard it is quite obviously a spiritual matter and not a physical food experience. Your insistence on making it a physical matter shows you really have no spiritual perception whatsoever.
I've answered this a couple of times now so I'm not going to continually repeat myself. Read my responses when I make them. Who exactly do you think you sin against when you sin?
The fact is you refuse to recognize sound hermeneutical exegesis in favor of RCC tradition and teaching. The fact is until you recognize your erroneous interpretation you won't ever understand the spiritual reality of who Jesus is in our lives. The Bible says, "God is spirit and those who worship Him must worship Him in spirit and in truth." You can't do that by making things physical.