yaddayadda, I understand your hostility to a new idea, especially one so seemingly blasphemous. Suffice for now me to say that many scholars in fact are shifting away from the 19th century idea of an "historical Jesus" because of both positive evidence and the deafening silences from history and Christian writings. There will always be 'radicals' and conservatives in any reputable field of study, that doesn't suggest arrogance, stupidity, or stubborness. It does suggest the waters are difficult to navigate and there may be a shift in paridigm in the works. As far as motive, I'd love nothing better than for there to surface some historical evidence for an historical person at the core of the stories. That would no doubt be of more value to critics of divisive Fundamentalist literalism than anything else.
BTW, I'm increasingly confident the Q hypothesis should be set aside in favor of the simpler Farrer/Goodacre. That's another example of overturning a convention that will likely take many years.
Continue studying, and I suggest reaching out to different ideas if for no other reason but to better understand the other side of issues. Doherty's book would be my first recommendation.
When you say:
clear themes, motifs, that come through each gospel that can only really be explained as the striking impact, impression, that Jesus made on those who heard him and saw him right from the oft.
It is the Gospel themes and motifs that are one of the best arguments against an historical Jesus. Near all the motifs and themes are clearly drawn from Jewish idealizations of Sophia,Logos,Light, Son of Man, etc. along with OT midrash of stories about Moses, Joseph et.al. Many of these idealizations of course were adaptations of similar concepts in the greater religious environment that included healing, teaching, dead raising, water walking, godmen and exalted humans, and wandering sages. To be sure anyone with a religious message in that period would natuarlly reflect many of theses themes, but its the combination of evident conscious manipulation of the story by the Gospel writers to better exploit those motifs, the lack of biographical awareness of any earthly Jesus by Paul, and the lack of consistancy in the images of Jesus in the abundant early noncanonical Christain writings that strongly suggests the literary nature of the character Jesus. He appears to be an embodiment of all that the writers idealized. Perhaps that's a great reason many secular scholars cling to the idea of an historical Jesus, we all love the lone hero who fights for the weak, we can't help but wish he existed.