I am backing down a bit from my assertions concerning Peter. My fascination with early Christianity is a bit scary since I don't have practical use for it. Many times I've read by reputable scholars that Peter being in Rome is only legend. There is a slight chance he was there. I don't know the details. The authors contrast Paul for whom there is no doubt he was in Rome (maybe b/c of Romans, outside sources) and no doubt that he was executed as a Roman citizen. The Peter record is murky. The NT was n ot written until a later point in time so church legend infiltrated the narratives.
It strikes me odd, too, b.c Peter has one of the most strongly defined personalities in the entire Bible. The Indian churches which I only found out about recently believe strongly from very early dates that Thomas is associated with them. I don't know what scholars believe about Thomas. The people believe it. Peter seems strongly entrenched in Jerusalem with James. Does anyone else wonder why the NT does not contain more info. about the carrying of the gospel. For me, the act of encompassing the Holy Spirit and spreading the good news is just as important as the gospels and epistles.
I feel that different apostles or disciples empahsized different teachings. Of course, St. Paul claimed a different link to Jesus and prevailed in setting orthodoxy. We studied why Christianity as we know it survived and variants that were just as legitimate declined. Social and political factors were mentioned. Certain forms of Christianity were more survivable through multiple generations.
I love the idea of doubting Thomas, the apostle with whom I most identify, becoming fearless and reaching India.
I've also wondered how the beloved disciple (never identified as John expressly in the Bible) did not play a more crucial role post-Resurrection. Why don't we know what Mary Magdalene did? She was not the sort to just disappear (of course, the answer to that one is obvious).
Another thing that always strikes me is that for the most part the Gnostics use the sayings and even narratives in broad stroke. Their interpretation, however, is radically different. If one were a Gnostic, one would assume Gnosticism had legitimacy.