The topic of how to quantify social events and experiences has been previously touched on only briefly. Such interactions are complex and while the rules to cover need not be complex, there should be more than one just stage to them. Also considerations should be made for less numerically tangible elements to these situations. The rules should also stay out of the way of the playing the characters' roles and enhance what they are doing, not replace them. Of course the amount of how much it aids and is separate will wary according to not only the players involved, but also from situation to situation. Some scenes and results could be resolved simply with a single roll and a brief narration while others will be longer form.
Any rules begin with the character statistics or attributes. The key stats are Charisma and Will, Mental Affinity and Mental Endurance, Personality and Intuition, or whatever they are called in your game. Having two stats are helpful and they will have other purposes beyond how they will be used socially. One stat should cover how well the character naturally gets on with or deals/interacts with other people. The other stat works to determine how easily the characters are swayed by other people.
Social skills and learning come next after the natural inborn social strengths and weaknesses are determined. Most of those skills were covered such as social networking, debating, seduction, and streetwise (or illegal contacts and services). One that did not come up, but works essentially the same despite the different knowledge needed and way of handling compromise, is diplomacy. There, more than anywhere else, a character could be dealing on behalf of someone else's interests besides their own with only pay or even just satisfaction to be earned from it. Diplomacy covers mediation or mediation could be it's own skill. The differentiator between the two is politics, though some level of politics is involved even when government, law, or finances are not involved. Another unmentioned skill would be bartering. Plus there are no doubt more you could layout or make use of when writing.
Music: A Charge to Keep by Iced Earth and Wicked Witch by Demons & Wizards.