How do guilds fit in?
You will be able to attack, loot, snoop and kill fellow and rival guild members without penalty.

Will being killed in guild warfare lower my stats if I am a murderer?
Yes, because you were a murderer.

How will I know a member of my guild?
They and their name will be GREEN when your mouse pointer is over them, unless they are a murderer in which case they will still appear RED. Also, if they are a criminal, or an aggressor they will appear GREY.

How will I know a member of a rival guild?
They and their name will be ORANGE when your mouse pointer is over them, unless they are a murderer in which case they will still appear RED.

What happens if I am killing a rival guild member or even a member of my own guild and they resign?
They won’t be able to report you if that is what you are asking.