I can confirm the duplicate ores. They exist for the gravel ores as well--iron, aluminum, gold, tin, etc.
The server seems to crash if I leave it running overnight.
Also, in my current world I can't fire a bow made with tinkers construct. I created a new server and cheated a bow and it works, so I'm trying to figure out it it's my class or something else. I made the exact same type of bow and arrows so I know it's not a particular material type.