A few mini-tips on farms and markets.
You will likely need to INTENTIONALLY lower the efficiency of the farms by placing the foundations in order to prevent them filling up quicker than the warehouse can drain it. It will not auto-start once it stops. It will just drain and remain stopped.
Warehouse trades are weighted, and need to match at both ends.
If I set a trade of "Slate" for "Granite" at a 1:1 ratio. I can ONLY trade Slate for Granite.
If my neighbor has a trade of "Granite" for "Slate" at a 10:1 ratio, we WILL TRADE at an average of our rates. I will send 5 Slate, and he will send 1 Granite. You CANNOT PREVENT THIS except by cancelling the trade route.
If I set a trade of "Slate" for "Stone" at 1:1 ratio, I can trade Slate for any other stone. Weighted ratios still apply. Some 'evil' person can set a bunch of "Marble for Stone" trades at 1:100 and if you have a route you will send 50:1 in return.
Gold earned is based on distance (in grids) but currently everything is 1 because there is only INTER-grid trading. Gold earned is PER trade, at either 10 gold for two different companies trading, or 5 gold for inter-company trades. (trading with your own markets)
You can set a market to private and have a few of them on one grid and just set a bunch of 1:1 trades between them to passively generate gold.
Warehouses will stop collecting (I think) if they fill on weight, but not on slots? This one is weird.