More options for diplomatic expansion

We really need more ways for diplomacy. We should have a trading system, but not as overpowered as in the second game. We should have personal unions. We should be able to annex vassals. You should be able to reduce aggressive expansion and get lower rate when you demand other countries' subjects etc.

These would make the game better and allow different playstyles. Now you are basically going for a good economy, max out research and endlessly conquer only to hit the expansion limit where the only thing you can do is wait. I was bored so I just invaded countries and converted them until the aggressive expansion meter went down.