The entire server is saved just prior to a frenzy and completely restored when it ends. Frenzies occur about once every two weeks, and are announced in advance. If you plan on logging off during the frenzy, just make sure your character was in a safe place when it began. Since that's where you'll be when the server resets, you don't want to be in the middle of a dungeon or the woods. The main goal of Meridian 59 is still correctly focused on the interaction between players.
Most people are very accommodating, and are willing to help new players learn the ropes.
I was reading a note that a new player posted on a message board within the game who got quite involved with his character. He acknowledged that it was probably his own fault, and was still having a great time playing the game. Player killing still goes on, but it's rare to see a blatant incident happen very often. While there will always be those that try to spoil a good thing, for the most part players respect each other and have fun. Technology-wise, the Meridian game engine still hasn't had a decent upgrade.