I am only a fan of history, by no means an expert. When it comes to early Christianity (the state of Judaism preceding Christ's birth through the writing of the New Testament), the only source I have is Bart D. Ehrman. I have watched lectures and listened to his interviews.
As I understand it, Ehrman's basic analysis of early Christianity is:
All of these facts make sense to me, though that is probably partially because I am an atheist and it fits my worldview. Therefore I am skeptical simply because of confirmation bias.
So, are there any other historical analyses of early Christianity that I should know about? Or is everything I listed simply accepted as fact, much in the way biologists accept evolution by natural selection, and the academic debate is over other details?
No, they are not simply accepted as fact like biologists accept evolution by natural selection and academic debate is over other things.
You really need to read other authors in the field of New Testament and Historical Jesus studies. Ehrman is a great read, but his popular works tend to simplify things in ways that academics are unhappy over, because he presents some things as settled that are far from settled.
Ehrman writes about a range of topics; I would be happy to provide a reading list for some broader engagement if you want to specify a little more precisely. In particular, I think you want engage more conservative and more radical scholarship in these areas.
I would say Ehrman is firmly in the mainstream on almost everything he writes. However, history isn't like biology; there is a paucity of records and data on the early centuries of the Christian era that keep us in the dark about how Christianity really started. There is not a single artifact related to Christianity — whether an inscription, manuscript, or anything else — that can be dated to the first century of the movement. We have no contemporary records about Jesus from any historian and are forced to come up with plausible but unprovable theories that explain the movement and the form of the New Testament scriptures as we have them today.
Ehrman's paradigm is quite plausible, but you'll find that every scholar has their own take on it. Two other mainstream authors you might want to check out are John Dominic Crossan and Geza Vermes.
On the more religious side of things, of course, you will find many religiously conservative scholars who prefer the Church's traditional view of things, including all the supernatural bits. Some of those scholars may have good insights, but obviously many of their conclusions are determined from the outset, and therefore suspect.
There are also secular scholars with less mainstream views. Examples would be Robert Eisenman (who connects Christianity with the Dead Sea Scrolls community) and Thomas L. Brodie (a Dominican priest who thinks Jesus was a purely mythical character).
I'm in the middle of reading N.T. Wright's Jesus and the Victory of God and I am really enjoying it. It was published in the early 1990's so he doesn't interact with Ehrman, but he does analyze the work of some of the other scholars mentioned already: Mack, Crossan and Vermes.
Wright is probably the foremost academic voice advocating an orthodox Christian (i.e. conservative) view of Jesus, 1st century Palestine and the books that came to make up the Christian Bible. As an ordained Anglican, he obviously brings in his own presuppositions, but so do other scholars.
Early Christian Doctrines by J.N.D. Kelly was a great read.