Frogboy,
I've noted this idea to you in small parts a few times, but thought I would provide the idea in detail here. First note, this idea came from Stardrive 2, it is not my idea.
In this version of diplomacy, each race has a "tolerance" number with each other. This represents the races trust and willingness to deal with you.
When you go to make a deal, each item on the table adds a value against your tolerance score. If it goes too high the deal cannot be made. Even if its a fair deal, your race is just not yet ready to commit that much faith in the other side.
After a deal is made, your tolerance goes down for a time and lower builds back up. As deals complete, your total tolerance with that race increases, and you can make greater and greater deals.
In SD2, diplomacy bonuses do not get you "better deals". It instead raises tolerance, allowing you to make bigger and more frequent deals.
This system has several benefits:
1) Diplomacy is more realistic. When two people meet each other, they don't offer each other their entire tech horde in exchange for the others.
2) Diplomacy bonuses make more sense. In real life, diplomacy is about making good deals the other side will accept. Even if both sides like each other, they aren't going to make deals that are not favorable to them....yet that is commonly how diplomacy bonuses work. In this system, diplomacy bonuses encourage a civilization to "deal more" and "deal big", but they still have to make fair and equitable deals.
3) Diplomacy becomes a growth and evolution. This system allows for diplomacy to grow with time. Races that work at deal making ultimately can do much better business with their neighbors, which is both realistic and fun.
4) It can simulate "sudden diplomacy events" well. If there was a faux pas event for example, you could do a big decrease in tolerance levels to represents a race's sudden hatred of you. But again....that doesn't stop deal making....a good deal is still a good deal. It just means your ability to deal is much more limited, and you have to think about what deals you are willing to make.
5) Ultimately....it increases the thought that goes into diplomacy. Right now, diplomacy can feel like "throw this in, try to get this, get the bars even". With tolerance, you have to really think about what you want and what you are willing to give....you have to both work the tolerance bars and try to come up with a good deal. Deal making becomes a craft not just something you do.
This system is one of the gems of SD2, and its well worth getting familiar with.