So, It sounds like Kirby came up with Spiderman a while ago but changed it to the Fly. Then later Kirby presented his idea for Spiderman to Stan and Ditko told him it was too similar to the Fly and Lee came up with his own version for Spider-Man, which Ditko added to and drew. (inlcuding the teenager with problems who only gets more problems when he becomes Spider-Man, and is hated by the media)
What I want to know is, along with where those 5 pages are of Spiderman) how much of Kirby's original Spiderman idea did Lee and Ditko use? Did Kirby's have Spider-Man's powers?
It sounds like, from the stories, that Spiderman and Spider-Man were too different. but does this mean that without Kirby's original idea Stan wouldn't have come up with Spider-Man/Peter Parker?
And does that mean that the whole story about seeing a fly crawling on the wall gave Stan Lee inspiration to create Spider-Man?
From what I've read Kirby did feel the idea for
a Spider-Man character originated with him and Simon (least its been reported he said that in interviews).
However, if the 'Silver Spider' was the inspiration for Stan Lee, Kirby did not actually have a hand in that one's initial creation: Joe Simon created 'Spiderman' (no hyphen) in the early 50's with artist CC Breck, and changed the name to 'The Silver Spider' before submitting it to his publishers who rejected it. Kirby was approached later on to revise the original artists designs at Joe Simon's request when Simon resubmitted the idea, renaming the character as 'The Fly', which in turn was accepted and did see print.
Stan Lee has always maintained though that he came up with the idea of 'Spider-Man' (with a hyphen) via wanting to introduce a teenage hero and the whole fly crawling on the wall thing. Lee approached Kirby
after that who then looked back to his work with Simon when coming up with his submission.
Lee rejected that 5 page submission, thinking it was too 'heroic', so Steve Ditko was approached. Ditko noted how very similar Kirby's version was to already published 'Fly' (Ditko had also worked on that title) so Lee asked him to re-do everything, gave him the plot for the first story, and the rest is history.
As for what Lee/Ditko did take from Kirby's ideas...Well Kirby's Spider-Man was a teenager living with a grumpy Uncle and kindly Aunt. But that's seem to be pretty much where it ends. The costume was typical of Kirby's designs for that time: half mask, trunks over tights, pirate boots, etc (same base costume elements as Captain America), no spider logo, no web designs in sight. He also used a web gun, not wrist shooters, and if it was indeed just like 'the Fly' then his powers came from magic, not a radio-active Spider bite. The powers themselves I would imagine were the obvious given the name (wall-crawling, strength, etc)
So as for the Spider-Man we know coming to pass had Kirby
not pitched anything in? If Lee had already thought of doing Spider-Man
before going to Kirby then I would say yes. Kirby's input had influence in some aspects (the uncle & aunt deal), but nearly all of the Spider-Man that saw print came from Lee and Ditko.