an auto smelter would be a god send. basically it makes 1 bar at a time of whatever you set it to and will only begin if it has the required materials and fuel. (only available in single player) plz implement some way to progress metals without having to buy them. i was thinking having higher tier metals/materials be mine able with lower tier picks but at a significantly lower success rate, like 1/10 the success rate for each tier higher making the chances of getting better materials extremely low, but still possible. it would allow for the challenge run "No buying bars!"
Also, you could have the smelter and saw bench be purchase able and a mode where you don't start with them. another idea is a wood carving bench where you can place firewood to make handles for weapons and the quality of handle produced would depend on the quality of wood and your intelligence. my final idea is to make a hidden stat that depends on intelligence: prospecting! in short: every other level in intelligence increases the chances to get ore when mining. this could compound with the idea above, the ability to mine higher tier metals, but remember that a higher tier metal will have the severe reduction in ore chance and would require a LOT of intelligence to make the chance for higher ore reasonable.
ps. I LOVE YOUR GAME!!!