If I had to guess I would say that the doves represent peace or freedom (Most likely peace) and because the papers are compared to doves maybe they have something to do with freedom or peace. Let me know if this helps or if you need more.
To establish a dynamic romantic association of a very well known image, most of the people can find in his memory. In order to give that moment a romantic representation.
Explanation:
When writers want to describe with romanticism they tend to use stilistic resources. why? because they want to represent a really conventional image in a fantastic way. In this case, he wanted to say that the papers flew through the air like birds. But he says more than what he writes, because he expects the reader to use his imagination, he could have described perfectly every bird, color, size, they way it swept it's wings, but he left it to the imagination of the reader, he didn't want to describe the image he had, he wanted the reader to go back to his memories and establish that moment of his life with his book. Because he wanted to make it personal and private. He demanded imagination from the reader, not representation. It was really ambitious, because he expected that the reader could create a magic moment without knowing his ability to create them.
the meaning is obvious enough: when people die, the bad things they did often stick in people’s memories, while their good deeds are forgotten. As Antony goes on to say, ‘So let it be with Caesar’.
