My Thoughts on Propaganda:
I think propaganda should be seen as an iniative and a program, rather than a one-time action. All this programs should be formatted like this.
Civilization 'x' should feel 'y' about civlization 'z'.
Now the exact syntax and such will change as y varies. Also, x and z can be the same. I'll give what examples of y would be.
x and z can be any civ, including yours. If x and z is the same for you, its internal, such as increase support for war. If x and z are the same opoonent, your trying to influence their people, such as decrease support for war(war weariness). If x is you and z is opponent, then you are trying to make your people feel a certain way about another civ, whether it be increase or decrease freindliness. If x is opponent and z is you, then vice versa. If x and z are not you, you are trying to get other people to feel certain ways about another poeple. Examples would be trying to garner good relations between various states you trade from, or try ot instigate a war.
As for what y is:
Increase War Weariness - x and z the same.
Decrease War Weariness - x and z the same.
Increase Hate - x and z different
Decrease Hate - x and z different
Increase Unhappiness - x and z the same
Decrease Unhappiness - x and z the same
Increase Flip Chance - x and z different
Decrease Flip Chance - x and z different
Infiltrate Military - x is always you. if z is you again, it counts as counter-intelligence
Infiltrate Research - x is always you. if z is you again, it counts as counter-intelligence
Infiltrate Government - x is always you. if z is you again, it counts as counter-intelligence
AS for implementation. Once you discover writing, you can have one such propaganda program running at any moment. Once you have Propaganda Corp(Small Wonder avaliable with Printing Press), you can run as many programs as you feel like or have the money for. For each program you have running, you would have a slider that would determine how much money went towards that program. The settings would be simple such as Minimal(50%), Light(75%), Moderate(100%), Heavy(150%), Priority(180%).
Program Growth:
Each program would accumulate 'espionage points' based on how much you fund them. Think of it like research, except your results are different. At each new plateau, you would get higher levels of effectiveness(you citizens really hate the enemy civ, i.e. little to no war weariness). Also, the higher the level, the more missions that would become avaliable.
Espionage Missions:
You would still have missions, but they would appear when your programs reached the right level of investment. For example, whenever your Research Infiltration reached the right level, you could try to steal research, or steal scientists, which would cause research points to be transferred over. EAch espionage mission cost gold and espionage points(part of your network is discovered). Another example, if you want to increase hate of another civ, your program would eventually allow you to arrange and assassination of one of your political leaders and blame it on the other guy. Mission dealing with counter-intelligence would often appear only whenever you have enough investment. They also depend on the existence of espionage programs of opponents in your civilization. The Intelligence Agency would allow for much greater success and variety of missions.