Point one is all I read. That was enough.The perfect thing to come is not Jesus. Jesus had already came.
Chapter 13 is dealing with things that are "part" of something. Whatever the part of something is, the whole or complete will be the same.
They know "in part" because they were getting bits and pieces of revelation, they did not have the "whole" revelation as we have it.
If you have 4 parts/pieces of a pie, you don't have a whole pie until you put it together. Paul is talking about the revelation/word of God, not Jesus. We have it in the whole/completed form. They did not.