Did he exist?

Question

Kvod Harav, I have read many times, in articels quoting historians, that it is very possible Jesus actually did never really exist as one person, but is a conglomerate of many people. This theory would fit our versions, considering that we have differant names for the simialiar stories in our gemora, like when he used "kabalah" to walk on water, the gemorah says his rebbe flew above him, and releaved himself on his head, which u never find in their version,. Also, is there any basis for teh rumor that Paul was sent by the Tanaim to move christianity away from Judaism, and that he wrote Nishmas on his deathbed?