And you keep mentioning that "glide" at Kitty Hawk, that has a slope. Never been there, but how how much of a slope is there?
Even a 10 degree slope would have generated an enormous 130 pounds of thrust (the tangential weight of the plane (605 pounds) plus pilot (145 pounds)).
The total thrust generated by the two propellers was just 134 pounds (estimated by the Wright Experience project).
see also:
1903 Wright Flyer I
An insignificant 10 degree slope would have nearly doubled the available thrust from 134 to 264 pounds.
The slope in the picture is clearly above 10 degrees.
The 1903 Flyer taking off in his first flight on Dec. 17, 1903.