Is there a way to give the guild leader the control over what might be edited in guild chat? I am thinking if there is a way to edit without censorship, but its hard to come up with a way to be perfect. Perhaps a way to silence the over eagerness of the new or to remove the words of a spy/non member anymore?

The guild chat cannot be edited but guild forums can be. I think that is enough instead of going all Big Brother and Orwell's 1984 on your guild.