1.) well im not saying its a fact that NT borrowed anything but it is a fact that very similar religions existed before its origin.
as far as undermining it thats up to each individual
2.) again you are talking about TEACHINGS and not fact and those teaching do not account for the "traces" because the times are way off, that doesnt explain anything.
3.) your example doesnt work because it does deal with times lines, it doesnt fit. I know what you are trying to say but teachings arent facts and do nothing to explain the dramatically varying timelines.