Your analysis should begin with source criticism.
I have been doing that a lot.
I see you are using mostly Paul, but also Mark. I support your use of Paul on the grounds that it is a first person account and we can get some idea about the nature of Paul based on his multiple writings. Unfortunately, he gives us little historical context to assess his reliability.
Paul gave little historical context, true, but certainly enough to ascertain the past existence of a human Jesus, with some attributes (which cause problems for mythicists).
http://historical-jesus.info/6.html
We also do not have contemporaries who comment on Paul or who he is. We are pretty much reliant on internal analysis to assess Paul. Now when I say that, it's important to note that we still have to evaluate assertions in Paul individually.
Well, we can learn a lot about Paul by reading his epistles. What he wrote about an earthly human Jesus is against the grain relative to his great savior & Son of God.
If we had contemporaries who commented on Paul (and wrote about it in surviving writings), they certainly would see him very differently from each others. Some would be enthusiastic about him, other would hate him, depending if they were Pauline converts or enemies (and he had both of them). As a result we would not know anything about him for sure because of the very different opinions.
Furthermore, Paul gave many indications in his epistles on how he was seen by contemporaries and that was not often roses, but rather negative.
I do not see where you establish a foundation for using Mark as a source for historical data. The writing is of unknown origin. We do not know the purpose, biases, or general reliability of the author. We don't really know the context in which this writing was created nor the audience. If we are going to apply historical methods, we have to agree that no solid historical data can be culled from the Gospel of Mark.
Historians have to work with writings of unknown origin many times. Furthermore, because of the many added embellishment and fiction, the author was certainly not going to reveal his name and provide the date of writing. However, that does not mean there is not a backbone of truth in his gospel. And we can do that by default, by eliminating most of his words, for reasons which can be explained.
By reading carefully the gospel, we can in a large measure figure out the context, the biases, the original audience with its doubts, disbeliefs, concerns that the author was trying to answer favorably (in order to keep these Christians in the flock).
I am not a fan of whatever is called historical method (which has been "interpreted" & misused a lot). I rather see my inquiry as investigating a crime scene, looking for contexts (historical & religious & social), multiple various clues & dissimulated evidence, in order to minimally reconstruct the birth of Christianity and find the culprits.
Cordially, Bernard