Look, it's not all that complicated. I already wrote a rather long, involved post about how to use the diplomacy system to your advantage. The problem is that people don't want to do so. You don't have to be the world's "female canine" (?).
Stop trying to role-play your leader. That's ridiculous. This is not a role-playing game. This is a wargame. If you really need proof of that, try remove all the wargame elements, and see what you're left with. By my calculation, it's close to nothing, except theatres, the culture slider, and a cultural victory. The diplomacy system is essentially based on
Realpolitik. Basically, Realpolitik is based on a Machiavellian world-view where you take the most politically advantageous path, disregarding morality. If you want to role-play your leader, pretend you're Kissinger.
And, no, I'm certainly no developer, but if it's truly that important to you, I can use the SDK and the XML files to explain how the AI plays: it plays the exact same way that I'm telling you is the best way to play. Mechanically. The AI doesn't care how nice you are or whether you're playing Gandhi as a pacifist. It will declare war on you, mechanically, when your power rating drops belong a certain value. Yes, yes, I recognize you have the "right" to play however you want, but if you'd like to know how to use the diplomacy system to your advantage, I can tell you. If you want to role-play, then you'll come up against unfair game elements that break your immersion. Constantly. You know why? Because the game was not designed to facilitate this style of play.
I'll try to explain it all again, this time with simpler words and examples, because something is not getting through. Let's assume this is a Monarch or Emperor game, Pangaea or close to it, and Normal speed. I'll demonstrate how everything that happens in the game is by my plan. By manipulating the diplomacy system, I can control when war is declared, upon whom war is declared, and slow down a powerful competitor's research, when he threatens to overtake my tech lead:
4000BC: I scout my land. I discover Julius Caesar, Tokugawa, Isabella, Catherine, Mansa Musa, Huyana Capac, Roosevelt, and Cyrus. Somewhere off on an island, I later find Genghis Khan.
3000BC: Julius Caesar makes a demand. I give him what he wants, because I want to have better diplomatic relations with him. Notice, I do not "role-play" or whine about his demand. I use it to my advantage, and now have a +1 diplomatic modifier.
2000BC: By now, Isabella founds many religions and builds a few shrines. She spreads her state religion to most of the world, which switch to that religion. Mansa Musa is the sole hold-out, for he has founded his own religion. I take note of this and choose to ally myself with Isabella, against Mansa Musa.
1500BC: Caesar makes another demand. I could probably win a war against him, but I still give in, because I want to have allies later on in the game. When both he and I are in Representation, and I have positive trade relations with him, he'll probably jump to Friendly. I'll get free techs and resources from him, not to mention get lucrative foreign trade routes, which I wouldn't get, if I conquered him.
750BC: More demands and requests from Caesar. Again, I give in, even though I feel that my military is up to the task of killing his Praetorians.
200BC: Mansa Musa is dead, and I control the majority of his lands, including the shrine he built. I do not switch my state religion, because I want to keep positive relations with Isabella.
100AD: War breaks out among the faithful. Tokugawa and Caesar now hate each other, and they both want me to choose sides. I decide to attack Tokugawa, because he's Protective, and I think Protective is a joke. Also, I have previous goodwill established with Caesar, thanks to giving in to his earlier demand.
500AD: Tokugawa is dead. Caesar is growing more powerful. I make note of this and decide to ally myself with Caesar against any of his future enemies.
750AD: Catherine makes several ridiculous demands of me, and I tire of her. I declare war on her, bribing all my friends into war, as well, so that I don't get any diplomatic hits (-1, you declare war on our friend).
900AD: I discover Genghis Khan. He continues to be a thorn in my side for the next few hundred years, trying to extort techs and money from me. Seeing as how he can't even send any ships, I refuse each time. What's he going to do? Anyways, he's got his own religion, which means that everyone hates him. I don't want to upset my allies by trading with him.
1200AD: Caesar vassalizes Catherine. Caesar is just getting too strong. I decide to spread the religion Mansa Musa founded to all his cities, then use Espionage to change his religion, so that everyone hates him.
1250AD: Capac declares war on Genghis. What, are they going to pillage each others' boats? I agree to Capac's request that I declare war on Genghis. I'm aways for a cold war.
1300AD: Isabella declares war on Caesar, then comes to me, demanding I do the same. I do. I bribe all my friends into declaring war, as well.
1400AD: Genghis comes to me seeking peace. I accept. Not a single fishing boat has been pillaged by anyone.
1500AD: Capac comes to me again, wanting war against Genghis. Genghis Khan gets his ass handed to him when I trade Astronomy to all my allies, organize a war against him, and his backward civilization is finally put out its misery.
1700AD: It's a long, painful process, but Caesar is finally dead, along with Catherine. I annex the majority of his land, making sure to bribe the AIs into settling with him before any of them can turn him into a vassal. I don't want a repeat of the Catherine Vassal Debacle.
1800AD: I finish the Apollo Program. Cyrus quickly follows. I thought I had a huge tech lead, but that is not so, apparently. Checking the demographics reveals that I'm actually second to Cyrus in most categories. I don't want to face Cyrus in battle, because he's both strong and Friendly, which means that I'll have to use sneakier methods. I change my research from SS techs to Mass Media, so that I can build the U.N.
1850AD: I build the U.N., get voted in easily, and call a vote for Environmentalism. Cyrus, of course, defies it, because he wants to stay in State Property. I trigger a diplomatic victory, out of curiosity, but it turns out that Cyrus is my opponent and has enough votes to block my victory. I don't want to attack Cyrus, mostly because I'm lazy and such a large war would take hours.
1860AD: After repeatedly defying the U.N. resolutions, Cyrus' cities are rioting. He finally accepts Environmentalism, and his finances tank. I also bribe him into adopting civics that don't benefit him, such as Serfdom or Nationhood.
1920AD: Isabella, who normally doesn't tech very quickly, is catching up to me and starting to make many SS parts. I begin sabotaging her projects, destroying her laboratories, and bribing other AIs to cancel their deals with her.
1950AD: Predictably, Isabella declares war. The war is a short one, however, because everyone
LOVES me, and I've made sure they dislike her. I bribe my allies into the war, and let them take her cities. I'm too busy with building SS parts.
1955AD: Capac spontaneously developes a hatred for Roosevelt, who's been pretty quiet the whole game. I instantly bribe Capac into making peace, so that he doesn't force me to choose sides. My military is a little thin, since I've been spamming SS parts.
1965AD: It's getting pretty late in the game, and I'm disheartened by all the wars that have slowed down my SS win. Still it looks like I'll be launching in a few turns.
1967AD: I launch, and Capac declares war on
me this time. Crazy bastard. Okay, fine, we'll have a stupid 15 turn war, while I wait to win the game.
1970AD: I suddenly remember that the UN hasn't banned nukes yet, and Capac built the Manhattan Project. This is where having friends really comes in handy. I call for a vote to band nukes, and it passes. Capac is the only one to vote no.
1980AD: I win a late SS victory and get something like 40K points. Maybe if I'd conquered the world in 1200AD, I could have gotten triple the points, but I like reaching the modern and future eras, where I can nuke people and send in paratroopers. It also allows me demonstrate some Modern-ish diplomacy, such as using the U.N. resolutions to your benefit.
Okay, I hope this illustrates what I've been talking about.
This is not a real game that I've played, but it consists of anecdotes from many different games that really did happen.
