Barring the need to prove a historical Jesus because at this point believers and (most) historians already do
All historians of this period.
I've often said that using the bible to prove the bible is futile.
However, that argument is fallacious. The NT represents the various strands of tradition which may be compared with one another, like Josephus may be compared to Philo. The bible is not a single work (as I know you are aware). It represents numerous texts by numerous authors. At times, these texts (especially when they are independent of each other) may be compared with one another.
The gospels were written close to the time they describe (as far as ancient history goes). There is good reason to believe that the authors were in a position to know a great deal about Jesus. There is independent evidence outside of the NT which testifies to a fair degree of control of the transmission of the Jesus tradition. In short, there is good reason to believe that the sayings and teachings of Jesus were reliably recorded (to debatable degree) in the gospels.
Now we must question, considering "Yeshua" never wrote anything and everything that is attributed to him saying something
The same might be said for Socrates. Do you believe he is historical?
Then it is a guestimate because we really have no way of proving he said these things.
Again, we have no way of proving ANYTHING in history (this is why there are people who actually deny the holocaust). As a matter of fact, you can't prove anything beyond ANY doubt (can you prove this isn't all a dream you are having?). This is nowhere more true than in ancient history. However, there is more evidence for Jesus than all but a handful of ancient persons.
The NT (4 gospels) are an easy read. They're not complicated at all.
Not on the surface, no. But I think it is important to keep a few things in mind (some of which I am sure you know already). The gospels you are reading are translations, which means you are not directly accessing the texts. As far as a general understanding of the texts is concerned, this isn't important. However, for indepth analysis it is. Also, the evidence of orality in the gospels is stamped into the text. It was the type of indepth analysis I just referred to that first revealed much of the gospels are various logia strung together with an overall narrative superimposed upon these older traditions. Just reading the gospels in the way you describe isn't sufficient for understanding them on this level.
Furthermore, my comment about you lack of possible lack of familiarity with ancient soruces was not about the gospels at all (and if I am wrong, and you have read a good deal of ancient history, I apologize, but I would appreciate if you could tell me what). The point I was making was that people who doubt the gospels and then point to various historians who don't mention him often misunderstand not only the amount of evidence available from ancient times but also the nature of the evidence. If you were to look at many ancient biographies (such as those by Diogenes Laertius, or the "life of Apollonysus of Tyana") you would find that although they are "biographies" of sorts, and "history," they are far less historical than the gospels. They are often removed by over a century from the events they described. With the gospels, the authors are much closer to the events and teachings of Jesus. Close enough that it is possible to say a fair amount about Jesus above and beyond "he was historical."
Some of it parallels other pagan stories, maybe not scene to scene, line for line etc. but comparatively there are some similar elements there
I would suggest that there is very, very little in common between the gospels and pagan myth. Even the "dying and resurrecting" god part is very different. Often enough, the so-called "dying and resurrecting" pagan gods aren't really resurrected per se (such as Osiris, who was really just put back together). Morever, these "rebirths" are much more cyclical. Basically, there is a wide, wide, gulf between the pagan myths and the gospels.
I simply think that the notion of a historical Jesus is a plausible hypothesis but it doesn't seem to have progress from that point.
You say it doesn't progress from that point, but how deeply have you looked into this? In other words, how much reputable scholarship from various views on the historical Jesus have you read (which do progress from that point)? As you obviously depart from their views as soon as they progress past this point, can you share the specific errors you see in the methodologies they adopt with which they do progress?