As the title suggests.
As the title suggests.
It doesn't disable friend requests, but rather it removes the notification window in the top right that you got a friend request:
http://img256.imageshack.us/img256/1707/img1339.png
Everything in this checklist doesn't get removed from the game as a feature, but rather if you remove the checkmark from the box then you won't get a notification about it
http://img231.imageshack.us/img231/1295/img1336.png
*Keep in mind that you cannot join a guild without receiving the notification as that seems to be the only way that you can accept an invite.