Have you read the Early Secular Writings Regarding Christ?
Of course not. There are none! (And I have seen and read your list.)
Going back a month or so in order to add this link which I believe is not behind the paywall that says basically what I wrote during this conversation.
Part 2 is on the gospels.
All of this is about trying to reconstruct the historical Jesus, the actual person and what we can actually say about him with confidence. It isn't so much about what the author's of the gospels are trying to communicate. The "Good News". Nor is it about the traditions and various religious teachings that developed since. Nor is it about what I ultimately believe. These are all different topics to me. One informs the other to an extent, but they also cloud each other.
Anyway, just wanted to add scholarly links on why I say that there are "no" early secular, and scant non secular writings to read "about Christ". There are some brief mentions of the man behind the movement, but what we can know about Jesus historically is very little.
But back the "God Problem" (how can there be suffering with an all-powerful, loving God?), the downside of apocalyptic ideas past and present (with possibly the "you must pick God and good or chose evil, no one can be in between" duality being the most problematic, and aliens, angels, and demons.