If you have enough armor (and patience) you can kill guards in a town without going PVP. I made a video explaining how, but incase the video doesnt work I'll explain what you have to do
You throw a Burning Blossom, from the Fire Festival into a friendly fire for the Buff.
The buff makes it so that when people attack you they take a relatively high amount of damage (about 68 for a lvl 67) per hit
And if you go to a town with low-ish level guards (the highest is probably 65, and even that's hard, for a pally at least) and stand there, let them attack you and they'll take the damage from the hits.
You dont go PVP though
here's the video
[ame]http://www.youtube.com/watch?v=LnkZCWEXVjQ[/ame]