i think we can get ressource by searching for them in the city in chest , we can't break block by hand but we need the game to give us tools , and also you can ge tthem from the last city you visit , they're would be different technology so some city would have no problem but they will ask you to help them to get highter in tech to a certain point ( but before that of course for realistic sake we need first to also upgrade the labotory so you can get some people to research) i think that would be cool also custom npcs mod(install the whole jar file in mods. not modjar or minecaft.jar) so they're would be labotory to research and even if the player has the ressource he can't craft certain object which he will can when researching (a sign will show you you can now make that in this world.) also remembering back in the tools thing you would depending on the tools can break different material , red matter pick can break any stone block then the dark matter one breaks diamonds and gold block ONLY(not ore) then diamond one break obsidian and brick. then the iron one break coal iron , and stuff like that they all break different stuff and red matter breaks all.