All of these discussions come to one single point in our game and that is all pointing to some changes in Diplomacy. One thing I would really like to see is a change in how the ai decides to go to war.
Eventually, operations short of war, like psyops (say, rigging elections, espionage, guerrilla conflicts and asymmetrical warfare, blockading, trade-related malfeasance, providing weapons tech or warships to opposing civilizations, sheltering pirates) would be great to explore in more detail, although they might be taxing on the AI. One such activity is already prominently featured: influence and planet flipping. I do think the current AI is too permissive of planet flipping. It would be ideal at some level to develop a more complicated relationship between quasi-hostile actions, natural competition (how close is someone getting to victory? Are they getting too powerful?), and the decision to go to war.
In the geopolitical situation today, certain powers (not to get too political) have made a habit of 'salami slicing,' slowly using influence, covert action, and political maneuvering to eventually effect a fait accompli in the long-term. For example, if GCIII ever considered the species of populations, one might be able to foment interspecies strife on a conquered planet to prevent the population from being used effectively for production, or to promote nationalism to stymie development and eventually 'reverse flip' a flipped planet.
To be clear, I do NOT want to start a discussion about current politics here... while they are a good example of the things I am talking about, I think these forums should welcome people of all nationalities, opinions, beliefs, and motivations. It is just a game, really...