I'm still confused by the trading system though. Because you have the option of allowing trading or not on your planets so does that mean that if someone sends a trading ship to my planets it gets turned away or does it just trade non-player used resources to generate some sort of income? Not to mention the option starts at off and you can only trade with other players so where is this trading?
From what I can gather, if your ship gets there and the player isn't trading, your ships are sent away. They won't be sent away from your own planets though (there's no mention of needing to agree to trade with yourself).
I think it's set to 'off' automatically is because it takes away your resources which you might be saving in return for currency and other resources (that you may/may not need). So it's a risk you take: you might get resources you need, but you might lose some you need too.
