(I say development of the Liturgy to emphasize that it is a thing growing, elaborating, refining and maturing what is already innate to it, unfolding from within as it were. I avoid the word "evolution" which might connote, to some, the random mutation of a thing into something alien and even opposite.)
Along those lines, I would differ from you mainly in emphasis. The 1st century A.D. agape meals did not, I think, exclude or contradict the idea that it is a sacrificial meal as well: the kernels of that idea are already contained in the Hebrew Scriptures which were diligently searched by the new Christians. From Genesis (Melchizedek) to Exodus (manna) to Malachi, there are types, foreshadowings, and prophecies of a new priesthood distinct from the Aaronic priesthood, a new and perfect sacrifice offered "by gentiles," offered in the "nations" from the rising to the setting of the sun, and a new and incomparably more wonderful bread from heaven.
And Christ Himself said "You must eat my Body and drink my Blood." Not just "You must eat my memory." And the writers of the Epistles have plenty to say about this.
So all the elements were there.
It was probably not until after the destruction of the Temple and the definitive barring of all the Christian groups from synagogues, that the sacrifice (temple) part and the readings-and-teachings (synagogue) part came together into an integrated Liturgical form for Christians. But what they "developed" had its roots in the Scriptures they already used, the teachings of the Apostles, and their long tradition of Jewish liturgical worship. These formed, from the very first, the template for their order of worship.
The sources are many, but for a wonderful summary of the history of the Mass I recommend The Mass of the Early Christians by Mike Aquinilina (Sunday Visitor Publishing, 2001). It is a great introduction. He presents a very Catholic view, which is okay, but does not exhaust the topic by any means. It's a good start.
I say development of the Liturgy to emphasize that it is a thing growing, elaborating, refining and maturing what is already innate to it, unfolding from within as it were. I avoid the word "evolution" which might connote, to some, the random mutation of a thing into something alien and even opposite
I know that, and you made that perfectly clear earlier. I emphasized evolve precisely for that reason. Primitive Christianity is a sui-generis evolution, a synthesis of the Jewish and Platonic, with a seasoning of Persian; a Hellenized Judaism if you will.
The 1st century A.D. agape meals did not, I think, exclude or contradict the idea that it is a sacrificial meal as well: the kernels of that idea are already contained in the Hebrew Scriptures which were diligently searched by the new Christians
Not all offerings to God were sacrificial, as they are not today. We dedicate or offer prayers, incense, thanks, etc. to God. But these are not sacrifices. Sacrifices are made for a specific purpose of invoking God to sacramentally (mysteriously) change things in return.
Melchizedek...
He is a problem figure for the Jewish theologians, but that doesn't necessarily mean he foreshadowed Christ. I recommend your read the Jewish take on him in Encyclopedia Hebraica (Jewish Encyclopedia) for a detailed and Bible-referenced take on him.
And Christ Himself said "You must eat my Body and drink my Blood." Not just "You must eat my memory."...So all the elements were there.
At the Last Supper, he simply said "do this in memory of me." If the "breaking of the bread" is a memorial act, then it is not a sacrifice. Of course, he blessed the bread, and since he was the High Priest, it is only proper for a priest, an icon of Christ, or alter-Christus in the Catholic tradition, to do that at the re-enactment. But he did not raise the bread nor offered it as a bloodless sacrifice for atonement at the Last Supper.
So, no, I don't see that all the elements were there.
Christian theology is a newly synthesized theology, first beginning with Paul and ending with John. Much of it was not what Jesus taught in the Gospel accounts, but what was synthesized from using an essentially different scriptural source, the Septuagint and, in John's case, Platonic Hellenism.
Much of Christian theology and worship was "built upon" by adding things that weren't there to begin with, the deuterocanonical books, for example, and to a great extent oral tradition of uncertain origin.
Your analogy to a developing baby is only remotely applicable here, since a human being, in addition to development, also experiences evolution due to specific life circumstances and 'information' that was added on that wasn't there when the embryo was formed.
The Church, being a living body, developed from preexisting material, but also evolved in response to events and realities she encountered and battles she endured in her life. If the Romans didn't burn down the Temple perhaps the Jews would have been more accepting of the Christian sectarianism and chances are all other forms of Judaism (the Alexandrian, Essenes, Sadducees, etc.) would have continued to co-exist with the Pharisees, and Chgristianity ewould could have continued to exist as a Jewish sect.
John would have never been able to openly proclaim Jesus a God equal to YHWH in all but Sonship. There would have been no need to. Christians would have continued to offer sacrifices in the Temple and attend synagogal services as separate events. Aaronic priesthood would have been the only legitimate institution, etc. Christianity would have probably resembled the Judaizers of the Jerusalem Church.
None of the events that shaped Christianity could have been predicted or accounted for at the very synthesis of the Christian movement, so development did take place initially, with evolution added to it and shaping the Church through the centuries.
None of the Aristotelian philosophy was part of Church theology until Scholasticism, and the western doctrine of divine satisfaction (Anselm) was unknown to the Church in the first millennium. Augustine's original sin was likewise a novelty to the Eastern Church as well as to the Jewish roots of Christianity. Even fasting took a life of its own. I see evlution taking place everywhere in the Church, even today.