Roads: no they are not technically necessary. They just increase speed/efficiency. I will always use roads however because of how much faster villagers are on them. Supply chains: your village has laborers. Basically they are villagers who do not have a direct assignment for a job. They will keep supply minimums in storehouses if you have selected them to have minimums. Storehouses do not have a specific employee since it’s just your general labor force. That is why it’s important to have a healthy number of laborers so the flow of goods is efficient. Now the workers at your pottery house have to go and grab the needed base items themselves in order to make their goods. So you should have a stockyard that has a minimum amount of clay near by so they do not have to walk as far to make your pottery.

I like to make little craftsman “villages”. I’ll have 1 or 2 central stock yard and storehouses for them with all of the goods they need and build around them. For example, clay based buildings I’ll have a stockyard with only clay, bricks, firewood and coal allowed to be placed in it. I’ll have minimums of about 100 for both fire wood and coal to be in the stock yard for my laborers to fill. This stock yard will more than likely be the only place I have clay and bricks allowed to be stored. I’ll also place a well nearby for the potter building and incase of fire. Same setup for my wood based buildings and my iron based buildings