(Sorry for the late reply, just found this thread and it's interesting enough I thought I'd contribute. :) )
Gorbacz wrote:
So guys, what do you think would be an appropriate favored weapon for Christianity?
/ducks under the table
The Longsword. DEFINITELY the Longsword. The angel at the gate of Eden had/has a flaming sword, and not to mention Luke 22:36 where Jesus tells his followers to sell their cloaks if they have no money to buy a sword.
That or the Staff.
(though as far as the Clerics, I have a pet peeve that they ALWAYS wear armor. There should be an alternate version that was built for use without armor, I think. There are plenty enough examples of it in history and religion. Don't tell me Moses wore fullplate. :P)
As for domains, I think you could work with the "pick any domain" rule, but I also think there would be some domains that would always go with the religion and some that will never go with it. For instance, Law, Glory, and Healing seem like they'd always go with Christianity, and I doubt you'd see Evil, Chaos, Madness, and Scalykind in there.