There are lots of agnostic positions, like there are lots of Christian position. I think Ehrman's makes the most sense. It's probably what I would believe if I weren't a Christian. Here's what I think a typical moderate agnostic would say: (Note that this is not what I actually believe.)
Jesus and Paul existed. But the Gospels and Paul's letters aren't completely accurate. There are lots of reasons that people can get things wrong, particularly when they weren't witnesses themselves and they're reporting something second-hand. But there are plenty of cases where people can get things wrong even when they saw them. Take a look at studies of faith-healers, e.g. Nolan's book "Healing." He documents pretty carefully cases where people thought they saw miracles but they really didn't. In some of his examples the healers were clever fakes, but in one case even the healer thought she was performing miracles. But she wasn't.
While many people think at least some of the Gospels were written by disciples, the Gospels don't claim it and there's no way to prove it. So a reasonable agnostic could believe that the Gospels are based on second- or third-hand information.
It's obvious that Christians experienced something after Jesus' death, but reasonable agnostics might think that it was some kind of subjective experience (i.e. a vision or dream) and not an actual resurrection. (But see N T Wright's defense of why the resurrection pretty much has to be real.) If Jesus wasn't resurrected, then he might be just like a lot of others who people thought were the Messiah but weren't.
Since Paul got most of his information about Jesus from Peter and other disciples, if they were wrong to believe that Jesus was really God, then Paul would not be to blame for getting it wrong. He certainly had some kind of experience personally, but again, people misinterpret experiences like that all the time. Not everyone who thinks God has spoken to them can be right.
William Lane Craig has an interesting comment about Ehrman. He thinks it's a mistake for Christians to say that Biblical inerrancy is essential for Christianity, although he believes it himself. Ehrman started out as an evangelical. Criag thinks Ehrman got in trouble when he started seeing evidence in his studies that the Bible isn't perfectly accurate, and he had no way to cope with that as a Christian.
Hedric, I don't know where your role-play ends, so I need to ask, where's the close quote?
I'm pretty sure you don't believe that the Gospels and Epistles weren't completely accurate, because they are completely accurate in the context of what the writers wanted them to portray. Are they historical documents? Not as we understand historical documents. They, the Gospels, are an afterthought-after 30 years or so of teaching the teachings of Jesus, someone decided it was time to write them down.
What we have to prove who wrote the Gospels is the Early Church Fathers, who say definitively that Matthew, Mark, Luke and John wrote the Gospels, and that they wrote them in that order. The furthest removed the authors could have been is that they taught their disciples, who wrote down what they taught. Since there were no distractions, like internet, phones, television and radio, the disciples paid attention and got it right, with the help of the Holy Spirit.
Regarding "some kind of subjective experience" we know that Jesus appeared to over 500 men at once. Group hypnosis, maybe? I don't think so...
Regarding how Paul got his information, it was not from Peter, it was from Jesus, on the road to Damascus, who gave Paul his information. And if you read Galatians, it was a long time between the time Paul was struck down on that road, and when Paul met Peter.
Regarding miracles and how God speaks to us, if we only want to believe that faith-healing or something extraordinary is a miracle, you're limiting God severely. Every breath we take is a miracle of God, every child conceived, the fact that the sun comes over the horizon. Regarding God speaking to us, he speaks to everyone, day in, day out, regardless whether you believe in Him or not. That's all about attitude, though.
Again, I'm probably speaking to that unknown, hypothetical agnostic, but even so, it's nice to be able to show said agnostic how weak his arguments really are. In a Christian way, of course.