I think it would be more fun if I could trade for any combination of any asset for any other asset.  And, without requiring the Tech tree research.

I'd like to trade say a bunch of resources for a Treaty, or a marriage for a Treaty, or a marriage and a resource for a Treaty.  Have the Tech tree limitations be removed so I could do this from day one, but make the Tech tree research a HUGE bonus to this. So maybe without the Tech tree it's likely you can only trade 10 for one but with it 2 to 1 is possible. 

The pre 1.1 implemention felt arbitrarily limiting.