i didnt like the 20 year minimum time for trade before you can opt out... i would like to easily threaten my way through deals... you know.... corner the oil market and control the world from my little island like terrotories

If this will happen in Civ4 you should realize that what goes for you goes for the AI too. I think it'll be quite annoying to have the AI threatening you every other turn.

Hmm... that AI line can be arranged. Like no double threats due to the same trigger, for one.

Interesting idea...
(you realize this is a pandora box, right?)

Sure, you can address the AI line but if you do that you should address the same thing for the human player too if you want to prevent a skewed gameplay.