i think that one solution to the ore in a world running out is having it respawn, but somewhere else. so, say you mine some ore in a cave in the forest biome, it begins respawning in an entirely different biome. Of course, i am really hoping that the guys add in the ability to jump between worlds, because that would be absolutely awesome, and so interesting.
2019-04-16: A new hotfix (0.9.5.7) is now available!
People won't run out of resources. They're there- people just haven't looked everywhere yet.
If the maps are kept to their current scale then I can see that happening. If it's done to 1:1 of our Earth, or unlimited then you simply have to double-back, or expand further for more resources. Not all that worried about such right now, even without a copy
If it's necessary then I'd suggest adding in vanilla NPC traders to assist you with trading items for others in a somewhat equal value going a bit J-RPG hard in bartering, even with over-simplified menus or whatever.
I doubt running out of ore will be an issue. Especially if the world will be endless. You'll just have to travel more. But it would take a LONG time to have to go far at all... The earth in RW is plenty deep.Haste is the enemy of knowledge.