First off, Christianity was illegal until the 4th Century. Underground, persecuted sects don't leave truckloads of documents lying around.
However, Ignatius of Antioch (d. 110) states clearly that Peter and Paul were in Rome.
Irenaeus of Lyons (d 180) states clearly that Peter and Paul were in Rome.
Those are just two examples I can think of off the top of my head. There are certainly others. Do you have any counterexamples?
The rock Christ spoke of was faith, not a man.
Which has nothing whatsoever to do with the question of where Peter was buried.
He wrote that around AD 200.
But neither Ignatius or Iranaeus report of Peter's death do they? The memory of the early church isn't 'crystal clear' on this issue it seems
Underground, persecuted sects don't leave truckloads of documents lying around.
Mysteriously somehow recorded copies of the Gospel were able to survive, surely a little note about Peter's death could have made it as well. That is if it happened as stated
Oh, I don't know -- the salamikazes seem to be doing a lot of that in Iraq and Afghanistan.... ;-)
True, but since when does it matter if we stay on track around here?