i'd like to post some ideas. No clue if anyone likes them or not so ill just write down what i have:
1) Melting of metals: Instead of using the smelter combined with the crafting menue how about adding a smelter with an own "inventory". I refer in this topic to a game called haven and hearth. there you need coal which can be used at fuel at the smelter and the ore that can be put into the "smelters inventory" which can hold up to 25 "items". Since ore is not stackable in that game i guess it would fit in here like it does in minecraft. Simply melting by time

2) Expanding woods: As we know in the game called "real world" (bad story but booojaaaah graphic) forrests expand if they have the space to do so. It would be nice to see a chance that new trees grow at the sorrounding of a forrest. Also maybe an increase of the time a tree needs to regrow (same as flowers, metals etc). That way materials are kind of "valuable".
3) Individual area/biomes/landscape: As i mentioned above it would be nice to see a individual landscape. Therefore it would be nice to to simply find metal in a cave but maybe really "dig" in the mountain. Like you can build a minehole and then expand the minehole by mining the tiles around the initial minehole. Maybe even without to know exactly which metals are down there. That way it would boost the economy

4) economy (should have put that to point 3): I would love to see an economy in the game. Like the marketplace in the initial town it would be cool to have the ability to build a marketplace and hire an npc that sells the items you offer. You can put a price up and the npc takes an ammount of 2% of the price as taxes/payment.
5) Currency: As i loved the mod in mincecraft and the barterstands in haven a currency improves the gameplay a lot. For example point nr.4.
Another possibilitie of a currency is point 6.
6) Buying land: With the use of a currency it would be nice to be able to buy land from an "gouvernment npc". Like 5 gold per tile. Therefore by asking the npc to buy land he could show up the map of the influenced area of the government and you could select an area tile by tile. For example you want to buy an area of 20x20 tiles it would cost you a total value of 2000 gold.
That way player could help to enliven the area.
Much more to come if wanted. otherwise ill stop here for now

Rador