Wider Trade Agreements
I have one new (maybe someone had it already) rule in mind.
We can make military alliances with other countries with up to 5 members (if I remeber correctly). My idea is to make trade agreements where more than just two countries can be united (e.g. "We want to make a trade agreemet all together."). That means that they all would have a trade agreement (TA) with each other, but must spend less AP to achieve it.
If making TA now with 5 other countries means 125AP to spend by one player, with new rule it will cost for example 75AP (to make TA of more than 2 members with no additional cost if more members). It will mean saving of 50AP. If you want to make TA with 10 countries, 175AP would be saved.
The limit for number of players should not be set, if, than should be higher than for alliances (at least 10 or 15 members).
It may need more work to be done by boehm. It may also motivate players to make such TA instead of single ones (or two-sided). The work would be done once and no further care needed (in most cases).
This TA could be named formally and some level of hierarchy could be there, managed by the players in diplomacy thread. It would make this game little more life-like or how to say it.
Please, think of it, try to imagine and make it real if possible.
Thanks for your attention.