Other idea how to complicate all stuff

So ideal is to start with wood structures, no complaining.

Then there could be made soil forms that would be used for pouring liquid iron to them.

Imagine simple process:

The furnace:
- would accept crushed ore and crushed coal (these may be crushed by stone blocks, or in start may be used default ores)
- would have slag output (like miner/recycler)
- would have pipe output for molten iron

The steel furnace
- will accept simple molten iron
- will create molten iron

Molten materials in The Cooler (simple or advanced with water input)
- simple molten copper - copper plate, copper wire
- simple molten tin (must be added, when used in bronze)
- simple molten bronze (may be skipped)
- simple molten iron -> iron plate, iron gear, iron rod, ...
- molten iron -> steel plate, steel ingot, ... and iron stuff cheaper
- ...

As example we could use all basic stuff from Captain of Industry game

interesting stuff, some of it is already kinda in? I presume you've seen it, but for example more complex molten alloy recipes, turning molten metals into intermediates, etc
some of this could defintely be used for hard mode, and i'll see if i can fit it into normal PM in anyway :]

I start creating concept of molten iron and copper.
You can check it, if you want:
https://mods.factorio.com/mod/CaptainOfFactory

For now, is it part of different mode, but in case we combine some of your graphical talent, we can move it further.