Yello. Just a though. Why not merge the "trade goods" option of the game with the trade routes? Like, you could only trade a good with another empire if you have effective trade routes between you (because, how do you bring those goods if you do not even trade with that other empire?)
and if the trade route if destroyed, and no other trade route exist between the supplier and the customer, and the customer loose all benefits from the trade route.
So, civs with more trade goods would be more pursued for trade than most of the others. And civs will try harder to keep the routes open.
And, what about an option that says : "I will sell you diplomatic translator for the next 2 years. The price are that and that technology. After that, you will have to re-sign another contract"
