Finally, resurrection as a bodily event: In the first century world, pagans universally denied resurrection
No, they didn't.
Seven ancient sources verify that the disciples suffered (and some of them died) for their faith: Acts; Clement of Rome; Polycarp; Ignatius; Tertullian; Origen; and Dionysius of Corinth (preserved in Eusebius). Of course, there is also the testimony of Paul himself.
With the exception of Paul and possibly Clement, none of those you list could have known the early disciples. And I don't deny that some of Jesus' early followers were martyred, but you have not established the essential point of your argument: that they died for refusing to renounce the physical resurrection of Jesus.
If we know some of the oral traditions as preserved in the New Testament, then we do in fact have that tradition today.
If Luke is an example of the kind of oral traditions that circulated among early Christians, we can be certain that those oral traditions were not necessarily reliable.
Can you support this claim with evidence?
I not only can, but already have. Read the post again. I don't have time to elaborate further right now, but I can do so after work.
If you don't trust the testimony of Acts then you can't use the account of Paul's conversion to support your point that these were spiritual encounters. Also, many writers (even today) can write accurately about events they did not witness themselves. A discussion of Gamaliel would be interesting but off-topic since I am not arguing here for the reliability of Luke as a historian.
The reliability of "Luke" as a historian is essential to your argument, though I am not claiming that everything in Acts is false, just that it must be approached with caution. And regardless of the reliability of Acts, I think it's relevant to point out that even "Luke" doesn't depict Paul as describing a physical encounter.
Of course Luke isn't the only one who believed in a physical resurrection. Three gospels, the disciples, and Paul himself taught resurrection as a bodily event (I'm sure we'll discuss this more later).
Of course "Luke" isn't the only one. I don't deny that the early Christians believed in a physical resurrection or even that some of the authentic disciples of Jesus did. I am saying, however, that such an extraordinary claim requires extraordinary evidence, and I think you've set the bar very low. You didn't respond to another question of mine, but I think it's a very important one:
At Salem in 1692, sworn witnesses told of having seen Sarah Good fly through the air riding a stick. In England, over a period of 150 years, hundreds of witnesses reported sightings of Spring-Heeled Jack. At Knock in Ireland in 1879, fifteen people witnessed the appearance of the Mother of God, St. Joseph and St. John. At Fatima in 1917, 70,000 people reported having seen the sun change colors and dance across the sky. In the U.S. in the 20th century, dozens of people reported having been kidnaped by extraterrestrials.
Do you really believe the most likely explanation for all these things is that all those people experienced what they thought they experienced? Or does it seem more likely that there's some other -- likely psychological -- explanation?