Here is a brief summary - The purpose of guilds and change for ore vein generation and different Y value generation was to transform the typical MC game into something more difficult. Therefore relying on your knowledge for where diamonds might be typically... won't be all that helpful. Might give a new outlook or interest in the game.
We do have mainly 18-21 year olds on the server. Some are older, and only a few are younger (that were grandfathered in).
We have a google document that goes over more about Guilds and restrictions on AFK/Automatic farming (if that’s your thing).