Well, this confirms you are going in a vicious circle. You have stated the same or similar objections a dozen times…at least.
The most of them would serve to throw to a wastepaper basket many philosophers, rulers and religious individuals in Antiquity usually reckoned as existent. For example items 1 to 6. We have already discussed this.
Other items are irrelevant, as the cases of Tacitus or Josephus. If you invalidate Josephus' testimony (I agree) we arrive to conclusion that there is not a primary source that confirms the existence of Jesus. I agree. We have profusely discussed this.
You incur in some mistakes. It is not true that all “biblical writers” (evangelists I suppose) said their sources were in the Old Testament. Paul says he went to Jerusalem and some data he gives do not correspond to the Old Testament but probably they were given by supposed witness or heard tales. Luke said his writing is based on writings that report direct testimonies. You needn’t believe them (neither I) but it is not true that all they say their gospels were thrown from the Old Testament. But it is irrelevant whether they connect or not their stories with Old Testament. See comment by Craig B #2776 , and my #2779 . And we had discussed this before.
In my comment #2382 I introduced the Pharaonic steles issue. You can see a lot of Egyptian inscriptions in
this page. You will find a lot of unreliable stories full of mythical features. I recommend you the incredible victory of Ramses II supported by Ammon in the Kadesh battle. Even though mythical or unreliable these inscriptions are studied by historians and have provided some interesting factual data. But we have yet discussed this.
Interpolations make dubious the literal value of the Gospels or some chronological ascriptions. But the core of evangelic accounts was well established in the second century. No historian (biblical or not) I know maintains that the Gospels would be radically redacted in the late second or third centuries. Interpolations can be contradictory to the exegetical aspirations about authenticity of some/many/all the
[delete where not applicable] passages, but they are irrelevant for our discussion because my argument to support the existence of Jesus is independent of the nature and origin of the source. It is to say, no Christian neither in the first nor in the second centuries would have invented a humiliating and degrading death for his god or messiah. It will be as we chose for a contemporary prophet to be executed as a paedophilic killer. Not very fit for catechesis.