Good thoughts.
Good questions.
To "fulfill" something means it lacked something to bring to it's fullness. The "law" and prophets lacked something. To me it was (spiritual) knowledge of truth. Jesus brought truth and light to the world. To the Jews first (since they were already a church seeking knowledge) and then the rest of the world, who would see it.
The Council of Jerusalem (48AD) reeks so much of the Jews maintaining their "physical" laws (Of Moses and Noah) that Peter, Paul and James just agreed to the Jews holding fast to the "old faith" while hoping that the "spiritual truth" would eventually become their thinking. This is the first contrast of a Christian Jew, and a Christian. The former led to the emergence of Catholicism. And why the OT was contained in the 4th century creation of the Bible.
The Jews wanted the best of both worlds. Circumcision was so important to them. They held to the physical, even though Paul told the Gentiles that it didn't matter.
Paul:
18 Is any man called being circumcised? let him not become uncircumcised. Is any called in uncircumcision? let him not be circumcised.
19 Circumcision is nothing, and uncircumcision is nothing, but the keeping of the commandments of God.
20 Let every man abide in the same calling wherein he was called.
Jesus really didn't cross that bridge, because it had nothing to do with him message due to it's physical nature (although he did use it to show the Jews how they violated their own sabbath laws by performing them).
The OT is physical with sparks of spiritual. It is gray, IMO. The Gospel is Light, revealing truth and the true God. The OT is in "part". The "perfect" has come. The "part" should be done away (with). Seeing through a glass darkly, yet face to face? May mean that the kingdom of God is within us and all around us, yet we can't see it.
Paul was speaking of love, not charity.
When the Latin (Catholic) Bible was translated to English, a great revealing happened.
The hierarchy of the Roman Catholic Church did not approve of some of the words and phrases introduced by Tyndale, such as "overseer", where it would have been understood as "bishop", "elder" for "priest", and "love" rather than "charity". Tyndale, citing Erasmus, contended that the Greek New Testament did not support the traditional Roman Catholic readings. More controversially, Tyndale translated the Greek "ekklesia", (literally "called out ones"[50]) as "congregation" rather than "church".[51] It has been asserted this translation choice "was a direct threat to the Church's ancient—but so Tyndale here made clear, non-scriptural—claim to be the body of Christ on earth. To change these words was to strip the Church hierarchy of its pretensions to be Christ's terrestrial representative, and to award this honour to individual worshippers who made up each congregation."[51]
To me, we fulfill nothing but to provide knowledge to our own spirit that beckons to understand "what is my purpose?". To save the soul.